parseip.c - vx32 - Local 9vx git repository for patches.
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parseip.c (3525B)
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1 #include "u.h"
2 #include "lib.h"
3 #include "ctype.h"
4 #include "ip.h"
5
6 char*
7 v4parseip(uchar *to, char *from)
8 {
9 int i;
10 char *p;
11
12 p = from;
13 for(i = 0; i < 4 && *p; i++){
14 to[i] = strtoul(p, &p, 0);
15 if(*p == '.')
16 p++;
17 }
18 switch(CLASS(to)){
19 case 0: /* class A - 1 uchar net */
20 case 1:
21 if(i == 3){
22 to[3] = to[2];
23 to[2] = to[1];
24 to[1] = 0;
25 } else if (i == 2){
26 to[3] = to[1];
27 to[1] = 0;
28 }
29 break;
30 case 2: /* class B - 2 uchar net */
31 if(i == 3){
32 to[3] = to[2];
33 to[2] = 0;
34 }
35 break;
36 }
37 return p;
38 }
39
40 static int
41 ipcharok(int c)
42 {
43 return c == '.' || c == ':' || (isascii(c) && isxdigit(c));
44 }
45
46 static int
47 delimchar(int c)
48 {
49 if(c == '\0')
50 return 1;
51 if(c == '.' || c == ':' || (isascii(c) && isalnum(c)))
52 return 0;
53 return 1;
54 }
55
56 /*
57 * `from' may contain an address followed by other characters,
58 * at least in /boot, so we permit whitespace (and more) after the address.
59 * we do ensure that "delete" cannot be parsed as "de::".
60 *
61 * some callers don't check the return value for errors, so
62 * set `to' to something distinctive in the case of a parse error.
63 */
64 vlong
65 parseip(uchar *to, char *from)
66 {
67 int i, elipsis = 0, v4 = 1;
68 ulong x;
69 char *p, *op;
70
71 memset(to, 0, IPaddrlen);
72 p = from;
73 for(i = 0; i < IPaddrlen && ipcharok(*p); i+=2){
74 op = p;
75 x = strtoul(p, &p, 16);
76 if(*p == '.' || (*p == 0 && i == 0)){ /* ends with v4? */
77 p = v4parseip(to+i, op);
78 i += 4;
79 break;
80 }
81 /* v6: at most 4 hex digits, followed by colon or delim */
82 if(x != (ushort)x || (*p != ':' && !delimchar(*p))) {
83 memset(to, 0, IPaddrlen);
84 return -1; /* parse error */
85 }
86 to[i] = x>>8;
87 to[i+1] = x;
88 if(*p == ':'){
89 v4 = 0;
90 if(*++p == ':'){ /* :: is elided zero short(s) */
91 if (elipsis) {
92 memset(to, 0, IPaddrlen);
93 return -1; /* second :: */
94 }
95 elipsis = i+2;
96 p++;
97 }
98 } else if (p == op) /* strtoul made no progress? */
99 break;
100 }
101 if (p == from || !delimchar(*p)) {
102 memset(to, 0, IPaddrlen);
103 return -1; /* parse error */
104 }
105 if(i < IPaddrlen){
106 memmove(&to[elipsis+IPaddrlen-i], &to[elipsis], i-elipsis);
107 memset(&to[elipsis], 0, IPaddrlen-i);
108 }
109 if(v4){
110 to[10] = to[11] = 0xff;
111 return nhgetl(to + IPv4off);
112 } else
113 return 6;
114 }
115
116 /*
117 * hack to allow ip v4 masks to be entered in the old
118 * style
119 */
120 vlong
121 parseipmask(uchar *to, char *from)
122 {
123 int i, w;
124 vlong x;
125 uchar *p;
126
127 if(*from == '/'){
128 /* as a number of prefix bits */
129 i = atoi(from+1);
130 if(i < 0)
131 i = 0;
132 if(i > 128)
133 i = 128;
134 w = i;
135 memset(to, 0, IPaddrlen);
136 for(p = to; i >= 8; i -= 8)
137 *p++ = 0xff;
138 if(i > 0)
139 *p = ~((1<<(8-i))-1);
140 x = nhgetl(to+IPv4off);
141 /*
142 * identify as ipv6 if the mask is inexpressible as a v4 mask
143 * (because it has too few mask bits). Arguably, we could
144 * always return 6 here.
145 */
146 if (w < 8*(IPaddrlen-IPv4addrlen))
147 return 6;
148 } else {
149 /* as a straight v4 bit mask */
150 x = parseip(to, from);
151 if (x != -1)
152 x = (ulong)nhgetl(to + IPv4off);
153 if(memcmp(to, v4prefix, IPv4off) == 0)
154 memset(to, 0xff, IPv4off);
155 }
156 return x;
157 }
158
159 /*
160 * parse a v4 ip address/mask in cidr format
161 */
162 char*
163 v4parsecidr(uchar *addr, uchar *mask, char *from)
164 {
165 int i;
166 char *p;
167 uchar *a;
168
169 p = v4parseip(addr, from);
170
171 if(*p == '/'){
172 /* as a number of prefix bits */
173 i = strtoul(p+1, &p, 0);
174 if(i > 32)
175 i = 32;
176 memset(mask, 0, IPv4addrlen);
177 for(a = mask; i >= 8; i -= 8)
178 *a++ = 0xff;
179 if(i > 0)
180 *a = ~((1<<(8-i))-1);
181 } else
182 memcpy(mask, defmask(addr), IPv4addrlen);
183 return p;
184 }