1 /*
2 * Generic address resultion entity
3 *
4 * Authors:
5 * net_random Alan Cox
6 * net_ratelimit Andi Kleen
7 * in{4,6}_pton YOSHIFUJI Hideaki, Copyright (C)2006 USAGI/WIDE Project
8 *
9 * Created by Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
15 */
16
17 #include <linux/module.h>
18 #include <linux/jiffies.h>
19 #include <linux/kernel.h>
20 #include <linux/inet.h>
21 #include <linux/mm.h>
22 #include <linux/net.h>
23 #include <linux/string.h>
24 #include <linux/types.h>
25 #include <linux/percpu.h>
26 #include <linux/init.h>
27 #include <linux/ratelimit.h>
28
29 #include <net/sock.h>
30 #include <net/net_ratelimit.h>
31
32 #include <asm/byteorder.h>
33 #include <asm/uaccess.h>
34
35 int net_msg_warn __read_mostly = 1;
36 EXPORT_SYMBOL(net_msg_warn);
37
38 DEFINE_RATELIMIT_STATE(net_ratelimit_state, 5 * HZ, 10);
39 /*
40 * All net warning printk()s should be guarded by this function.
41 */
net_ratelimit(void)42 int net_ratelimit(void)
43 {
44 return __ratelimit(&net_ratelimit_state);
45 }
46 EXPORT_SYMBOL(net_ratelimit);
47
48 /*
49 * Convert an ASCII string to binary IP.
50 * This is outside of net/ipv4/ because various code that uses IP addresses
51 * is otherwise not dependent on the TCP/IP stack.
52 */
53
in_aton(const char * str)54 __be32 in_aton(const char *str)
55 {
56 unsigned long l;
57 unsigned int val;
58 int i;
59
60 l = 0;
61 for (i = 0; i < 4; i++)
62 {
63 l <<= 8;
64 if (*str != '\0')
65 {
66 val = 0;
67 while (*str != '\0' && *str != '.' && *str != '\n')
68 {
69 val *= 10;
70 val += *str - '0';
71 str++;
72 }
73 l |= val;
74 if (*str != '\0')
75 str++;
76 }
77 }
78 return htonl(l);
79 }
80 EXPORT_SYMBOL(in_aton);
81
82 #define IN6PTON_XDIGIT 0x00010000
83 #define IN6PTON_DIGIT 0x00020000
84 #define IN6PTON_COLON_MASK 0x00700000
85 #define IN6PTON_COLON_1 0x00100000 /* single : requested */
86 #define IN6PTON_COLON_2 0x00200000 /* second : requested */
87 #define IN6PTON_COLON_1_2 0x00400000 /* :: requested */
88 #define IN6PTON_DOT 0x00800000 /* . */
89 #define IN6PTON_DELIM 0x10000000
90 #define IN6PTON_NULL 0x20000000 /* first/tail */
91 #define IN6PTON_UNKNOWN 0x40000000
92
xdigit2bin(char c,int delim)93 static inline int xdigit2bin(char c, int delim)
94 {
95 int val;
96
97 if (c == delim || c == '\0')
98 return IN6PTON_DELIM;
99 if (c == ':')
100 return IN6PTON_COLON_MASK;
101 if (c == '.')
102 return IN6PTON_DOT;
103
104 val = hex_to_bin(c);
105 if (val >= 0)
106 return val | IN6PTON_XDIGIT | (val < 10 ? IN6PTON_DIGIT : 0);
107
108 if (delim == -1)
109 return IN6PTON_DELIM;
110 return IN6PTON_UNKNOWN;
111 }
112
in4_pton(const char * src,int srclen,u8 * dst,int delim,const char ** end)113 int in4_pton(const char *src, int srclen,
114 u8 *dst,
115 int delim, const char **end)
116 {
117 const char *s;
118 u8 *d;
119 u8 dbuf[4];
120 int ret = 0;
121 int i;
122 int w = 0;
123
124 if (srclen < 0)
125 srclen = strlen(src);
126 s = src;
127 d = dbuf;
128 i = 0;
129 while(1) {
130 int c;
131 c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
132 if (!(c & (IN6PTON_DIGIT | IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK))) {
133 goto out;
134 }
135 if (c & (IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
136 if (w == 0)
137 goto out;
138 *d++ = w & 0xff;
139 w = 0;
140 i++;
141 if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
142 if (i != 4)
143 goto out;
144 break;
145 }
146 goto cont;
147 }
148 w = (w * 10) + c;
149 if ((w & 0xffff) > 255) {
150 goto out;
151 }
152 cont:
153 if (i >= 4)
154 goto out;
155 s++;
156 srclen--;
157 }
158 ret = 1;
159 memcpy(dst, dbuf, sizeof(dbuf));
160 out:
161 if (end)
162 *end = s;
163 return ret;
164 }
165 EXPORT_SYMBOL(in4_pton);
166
in6_pton(const char * src,int srclen,u8 * dst,int delim,const char ** end)167 int in6_pton(const char *src, int srclen,
168 u8 *dst,
169 int delim, const char **end)
170 {
171 const char *s, *tok = NULL;
172 u8 *d, *dc = NULL;
173 u8 dbuf[16];
174 int ret = 0;
175 int i;
176 int state = IN6PTON_COLON_1_2 | IN6PTON_XDIGIT | IN6PTON_NULL;
177 int w = 0;
178
179 memset(dbuf, 0, sizeof(dbuf));
180
181 s = src;
182 d = dbuf;
183 if (srclen < 0)
184 srclen = strlen(src);
185
186 while (1) {
187 int c;
188
189 c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
190 if (!(c & state))
191 goto out;
192 if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
193 /* process one 16-bit word */
194 if (!(state & IN6PTON_NULL)) {
195 *d++ = (w >> 8) & 0xff;
196 *d++ = w & 0xff;
197 }
198 w = 0;
199 if (c & IN6PTON_DELIM) {
200 /* We've processed last word */
201 break;
202 }
203 /*
204 * COLON_1 => XDIGIT
205 * COLON_2 => XDIGIT|DELIM
206 * COLON_1_2 => COLON_2
207 */
208 switch (state & IN6PTON_COLON_MASK) {
209 case IN6PTON_COLON_2:
210 dc = d;
211 state = IN6PTON_XDIGIT | IN6PTON_DELIM;
212 if (dc - dbuf >= sizeof(dbuf))
213 state |= IN6PTON_NULL;
214 break;
215 case IN6PTON_COLON_1|IN6PTON_COLON_1_2:
216 state = IN6PTON_XDIGIT | IN6PTON_COLON_2;
217 break;
218 case IN6PTON_COLON_1:
219 state = IN6PTON_XDIGIT;
220 break;
221 case IN6PTON_COLON_1_2:
222 state = IN6PTON_COLON_2;
223 break;
224 default:
225 state = 0;
226 }
227 tok = s + 1;
228 goto cont;
229 }
230
231 if (c & IN6PTON_DOT) {
232 ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s);
233 if (ret > 0) {
234 d += 4;
235 break;
236 }
237 goto out;
238 }
239
240 w = (w << 4) | (0xff & c);
241 state = IN6PTON_COLON_1 | IN6PTON_DELIM;
242 if (!(w & 0xf000)) {
243 state |= IN6PTON_XDIGIT;
244 }
245 if (!dc && d + 2 < dbuf + sizeof(dbuf)) {
246 state |= IN6PTON_COLON_1_2;
247 state &= ~IN6PTON_DELIM;
248 }
249 if (d + 2 >= dbuf + sizeof(dbuf)) {
250 state &= ~(IN6PTON_COLON_1|IN6PTON_COLON_1_2);
251 }
252 cont:
253 if ((dc && d + 4 < dbuf + sizeof(dbuf)) ||
254 d + 4 == dbuf + sizeof(dbuf)) {
255 state |= IN6PTON_DOT;
256 }
257 if (d >= dbuf + sizeof(dbuf)) {
258 state &= ~(IN6PTON_XDIGIT|IN6PTON_COLON_MASK);
259 }
260 s++;
261 srclen--;
262 }
263
264 i = 15; d--;
265
266 if (dc) {
267 while(d >= dc)
268 dst[i--] = *d--;
269 while(i >= dc - dbuf)
270 dst[i--] = 0;
271 while(i >= 0)
272 dst[i--] = *d--;
273 } else
274 memcpy(dst, dbuf, sizeof(dbuf));
275
276 ret = 1;
277 out:
278 if (end)
279 *end = s;
280 return ret;
281 }
282 EXPORT_SYMBOL(in6_pton);
283
inet_proto_csum_replace4(__sum16 * sum,struct sk_buff * skb,__be32 from,__be32 to,int pseudohdr)284 void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
285 __be32 from, __be32 to, int pseudohdr)
286 {
287 __be32 diff[] = { ~from, to };
288 if (skb->ip_summed != CHECKSUM_PARTIAL) {
289 *sum = csum_fold(csum_partial(diff, sizeof(diff),
290 ~csum_unfold(*sum)));
291 if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
292 skb->csum = ~csum_partial(diff, sizeof(diff),
293 ~skb->csum);
294 } else if (pseudohdr)
295 *sum = ~csum_fold(csum_partial(diff, sizeof(diff),
296 csum_unfold(*sum)));
297 }
298 EXPORT_SYMBOL(inet_proto_csum_replace4);
299
mac_pton(const char * s,u8 * mac)300 int mac_pton(const char *s, u8 *mac)
301 {
302 int i;
303
304 /* XX:XX:XX:XX:XX:XX */
305 if (strlen(s) < 3 * ETH_ALEN - 1)
306 return 0;
307
308 /* Don't dirty result unless string is valid MAC. */
309 for (i = 0; i < ETH_ALEN; i++) {
310 if (!strchr("0123456789abcdefABCDEF", s[i * 3]))
311 return 0;
312 if (!strchr("0123456789abcdefABCDEF", s[i * 3 + 1]))
313 return 0;
314 if (i != ETH_ALEN - 1 && s[i * 3 + 2] != ':')
315 return 0;
316 }
317 for (i = 0; i < ETH_ALEN; i++) {
318 mac[i] = (hex_to_bin(s[i * 3]) << 4) | hex_to_bin(s[i * 3 + 1]);
319 }
320 return 1;
321 }
322 EXPORT_SYMBOL(mac_pton);
323