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/ctype.h>
21 #include <linux/inet.h>
22 #include <linux/mm.h>
23 #include <linux/net.h>
24 #include <linux/string.h>
25 #include <linux/types.h>
26 #include <linux/percpu.h>
27 #include <linux/init.h>
28 #include <linux/ratelimit.h>
29
30 #include <net/sock.h>
31 #include <net/net_ratelimit.h>
32
33 #include <asm/byteorder.h>
34 #include <asm/uaccess.h>
35
36 int net_msg_warn __read_mostly = 1;
37 EXPORT_SYMBOL(net_msg_warn);
38
39 DEFINE_RATELIMIT_STATE(net_ratelimit_state, 5 * HZ, 10);
40 /*
41 * All net warning printk()s should be guarded by this function.
42 */
net_ratelimit(void)43 int net_ratelimit(void)
44 {
45 return __ratelimit(&net_ratelimit_state);
46 }
47 EXPORT_SYMBOL(net_ratelimit);
48
49 /*
50 * Convert an ASCII string to binary IP.
51 * This is outside of net/ipv4/ because various code that uses IP addresses
52 * is otherwise not dependent on the TCP/IP stack.
53 */
54
in_aton(const char * str)55 __be32 in_aton(const char *str)
56 {
57 unsigned long l;
58 unsigned int val;
59 int i;
60
61 l = 0;
62 for (i = 0; i < 4; i++) {
63 l <<= 8;
64 if (*str != '\0') {
65 val = 0;
66 while (*str != '\0' && *str != '.' && *str != '\n') {
67 val *= 10;
68 val += *str - '0';
69 str++;
70 }
71 l |= val;
72 if (*str != '\0')
73 str++;
74 }
75 }
76 return htonl(l);
77 }
78 EXPORT_SYMBOL(in_aton);
79
80 #define IN6PTON_XDIGIT 0x00010000
81 #define IN6PTON_DIGIT 0x00020000
82 #define IN6PTON_COLON_MASK 0x00700000
83 #define IN6PTON_COLON_1 0x00100000 /* single : requested */
84 #define IN6PTON_COLON_2 0x00200000 /* second : requested */
85 #define IN6PTON_COLON_1_2 0x00400000 /* :: requested */
86 #define IN6PTON_DOT 0x00800000 /* . */
87 #define IN6PTON_DELIM 0x10000000
88 #define IN6PTON_NULL 0x20000000 /* first/tail */
89 #define IN6PTON_UNKNOWN 0x40000000
90
xdigit2bin(char c,int delim)91 static inline int xdigit2bin(char c, int delim)
92 {
93 int val;
94
95 if (c == delim || c == '\0')
96 return IN6PTON_DELIM;
97 if (c == ':')
98 return IN6PTON_COLON_MASK;
99 if (c == '.')
100 return IN6PTON_DOT;
101
102 val = hex_to_bin(c);
103 if (val >= 0)
104 return val | IN6PTON_XDIGIT | (val < 10 ? IN6PTON_DIGIT : 0);
105
106 if (delim == -1)
107 return IN6PTON_DELIM;
108 return IN6PTON_UNKNOWN;
109 }
110
111 /**
112 * in4_pton - convert an IPv4 address from literal to binary representation
113 * @src: the start of the IPv4 address string
114 * @srclen: the length of the string, -1 means strlen(src)
115 * @dst: the binary (u8[4] array) representation of the IPv4 address
116 * @delim: the delimiter of the IPv4 address in @src, -1 means no delimiter
117 * @end: A pointer to the end of the parsed string will be placed here
118 *
119 * Return one on success, return zero when any error occurs
120 * and @end will point to the end of the parsed string.
121 *
122 */
in4_pton(const char * src,int srclen,u8 * dst,int delim,const char ** end)123 int in4_pton(const char *src, int srclen,
124 u8 *dst,
125 int delim, const char **end)
126 {
127 const char *s;
128 u8 *d;
129 u8 dbuf[4];
130 int ret = 0;
131 int i;
132 int w = 0;
133
134 if (srclen < 0)
135 srclen = strlen(src);
136 s = src;
137 d = dbuf;
138 i = 0;
139 while(1) {
140 int c;
141 c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
142 if (!(c & (IN6PTON_DIGIT | IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK))) {
143 goto out;
144 }
145 if (c & (IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
146 if (w == 0)
147 goto out;
148 *d++ = w & 0xff;
149 w = 0;
150 i++;
151 if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
152 if (i != 4)
153 goto out;
154 break;
155 }
156 goto cont;
157 }
158 w = (w * 10) + c;
159 if ((w & 0xffff) > 255) {
160 goto out;
161 }
162 cont:
163 if (i >= 4)
164 goto out;
165 s++;
166 srclen--;
167 }
168 ret = 1;
169 memcpy(dst, dbuf, sizeof(dbuf));
170 out:
171 if (end)
172 *end = s;
173 return ret;
174 }
175 EXPORT_SYMBOL(in4_pton);
176
177 /**
178 * in6_pton - convert an IPv6 address from literal to binary representation
179 * @src: the start of the IPv6 address string
180 * @srclen: the length of the string, -1 means strlen(src)
181 * @dst: the binary (u8[16] array) representation of the IPv6 address
182 * @delim: the delimiter of the IPv6 address in @src, -1 means no delimiter
183 * @end: A pointer to the end of the parsed string will be placed here
184 *
185 * Return one on success, return zero when any error occurs
186 * and @end will point to the end of the parsed string.
187 *
188 */
in6_pton(const char * src,int srclen,u8 * dst,int delim,const char ** end)189 int in6_pton(const char *src, int srclen,
190 u8 *dst,
191 int delim, const char **end)
192 {
193 const char *s, *tok = NULL;
194 u8 *d, *dc = NULL;
195 u8 dbuf[16];
196 int ret = 0;
197 int i;
198 int state = IN6PTON_COLON_1_2 | IN6PTON_XDIGIT | IN6PTON_NULL;
199 int w = 0;
200
201 memset(dbuf, 0, sizeof(dbuf));
202
203 s = src;
204 d = dbuf;
205 if (srclen < 0)
206 srclen = strlen(src);
207
208 while (1) {
209 int c;
210
211 c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
212 if (!(c & state))
213 goto out;
214 if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
215 /* process one 16-bit word */
216 if (!(state & IN6PTON_NULL)) {
217 *d++ = (w >> 8) & 0xff;
218 *d++ = w & 0xff;
219 }
220 w = 0;
221 if (c & IN6PTON_DELIM) {
222 /* We've processed last word */
223 break;
224 }
225 /*
226 * COLON_1 => XDIGIT
227 * COLON_2 => XDIGIT|DELIM
228 * COLON_1_2 => COLON_2
229 */
230 switch (state & IN6PTON_COLON_MASK) {
231 case IN6PTON_COLON_2:
232 dc = d;
233 state = IN6PTON_XDIGIT | IN6PTON_DELIM;
234 if (dc - dbuf >= sizeof(dbuf))
235 state |= IN6PTON_NULL;
236 break;
237 case IN6PTON_COLON_1|IN6PTON_COLON_1_2:
238 state = IN6PTON_XDIGIT | IN6PTON_COLON_2;
239 break;
240 case IN6PTON_COLON_1:
241 state = IN6PTON_XDIGIT;
242 break;
243 case IN6PTON_COLON_1_2:
244 state = IN6PTON_COLON_2;
245 break;
246 default:
247 state = 0;
248 }
249 tok = s + 1;
250 goto cont;
251 }
252
253 if (c & IN6PTON_DOT) {
254 ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s);
255 if (ret > 0) {
256 d += 4;
257 break;
258 }
259 goto out;
260 }
261
262 w = (w << 4) | (0xff & c);
263 state = IN6PTON_COLON_1 | IN6PTON_DELIM;
264 if (!(w & 0xf000)) {
265 state |= IN6PTON_XDIGIT;
266 }
267 if (!dc && d + 2 < dbuf + sizeof(dbuf)) {
268 state |= IN6PTON_COLON_1_2;
269 state &= ~IN6PTON_DELIM;
270 }
271 if (d + 2 >= dbuf + sizeof(dbuf)) {
272 state &= ~(IN6PTON_COLON_1|IN6PTON_COLON_1_2);
273 }
274 cont:
275 if ((dc && d + 4 < dbuf + sizeof(dbuf)) ||
276 d + 4 == dbuf + sizeof(dbuf)) {
277 state |= IN6PTON_DOT;
278 }
279 if (d >= dbuf + sizeof(dbuf)) {
280 state &= ~(IN6PTON_XDIGIT|IN6PTON_COLON_MASK);
281 }
282 s++;
283 srclen--;
284 }
285
286 i = 15; d--;
287
288 if (dc) {
289 while(d >= dc)
290 dst[i--] = *d--;
291 while(i >= dc - dbuf)
292 dst[i--] = 0;
293 while(i >= 0)
294 dst[i--] = *d--;
295 } else
296 memcpy(dst, dbuf, sizeof(dbuf));
297
298 ret = 1;
299 out:
300 if (end)
301 *end = s;
302 return ret;
303 }
304 EXPORT_SYMBOL(in6_pton);
305
inet_proto_csum_replace4(__sum16 * sum,struct sk_buff * skb,__be32 from,__be32 to,int pseudohdr)306 void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
307 __be32 from, __be32 to, int pseudohdr)
308 {
309 __be32 diff[] = { ~from, to };
310 if (skb->ip_summed != CHECKSUM_PARTIAL) {
311 *sum = csum_fold(csum_partial(diff, sizeof(diff),
312 ~csum_unfold(*sum)));
313 if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
314 skb->csum = ~csum_partial(diff, sizeof(diff),
315 ~skb->csum);
316 } else if (pseudohdr)
317 *sum = ~csum_fold(csum_partial(diff, sizeof(diff),
318 csum_unfold(*sum)));
319 }
320 EXPORT_SYMBOL(inet_proto_csum_replace4);
321
inet_proto_csum_replace16(__sum16 * sum,struct sk_buff * skb,const __be32 * from,const __be32 * to,int pseudohdr)322 void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb,
323 const __be32 *from, const __be32 *to,
324 int pseudohdr)
325 {
326 __be32 diff[] = {
327 ~from[0], ~from[1], ~from[2], ~from[3],
328 to[0], to[1], to[2], to[3],
329 };
330 if (skb->ip_summed != CHECKSUM_PARTIAL) {
331 *sum = csum_fold(csum_partial(diff, sizeof(diff),
332 ~csum_unfold(*sum)));
333 if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
334 skb->csum = ~csum_partial(diff, sizeof(diff),
335 ~skb->csum);
336 } else if (pseudohdr)
337 *sum = ~csum_fold(csum_partial(diff, sizeof(diff),
338 csum_unfold(*sum)));
339 }
340 EXPORT_SYMBOL(inet_proto_csum_replace16);
341
mac_pton(const char * s,u8 * mac)342 int mac_pton(const char *s, u8 *mac)
343 {
344 int i;
345
346 /* XX:XX:XX:XX:XX:XX */
347 if (strlen(s) < 3 * ETH_ALEN - 1)
348 return 0;
349
350 /* Don't dirty result unless string is valid MAC. */
351 for (i = 0; i < ETH_ALEN; i++) {
352 if (!isxdigit(s[i * 3]) || !isxdigit(s[i * 3 + 1]))
353 return 0;
354 if (i != ETH_ALEN - 1 && s[i * 3 + 2] != ':')
355 return 0;
356 }
357 for (i = 0; i < ETH_ALEN; i++) {
358 mac[i] = (hex_to_bin(s[i * 3]) << 4) | hex_to_bin(s[i * 3 + 1]);
359 }
360 return 1;
361 }
362 EXPORT_SYMBOL(mac_pton);
363