net: rtnetlink: decouple rtnetlink address families from real address families
[linux-2.6.git] / net / core / utils.c
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
31 #include <asm/byteorder.h>
32 #include <asm/system.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  */
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
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
81 EXPORT_SYMBOL(in_aton);
82
83 #define IN6PTON_XDIGIT          0x00010000
84 #define IN6PTON_DIGIT           0x00020000
85 #define IN6PTON_COLON_MASK      0x00700000
86 #define IN6PTON_COLON_1         0x00100000      /* single : requested */
87 #define IN6PTON_COLON_2         0x00200000      /* second : requested */
88 #define IN6PTON_COLON_1_2       0x00400000      /* :: requested */
89 #define IN6PTON_DOT             0x00800000      /* . */
90 #define IN6PTON_DELIM           0x10000000
91 #define IN6PTON_NULL            0x20000000      /* first/tail */
92 #define IN6PTON_UNKNOWN         0x40000000
93
94 static inline int xdigit2bin(char c, int delim)
95 {
96         if (c == delim || c == '\0')
97                 return IN6PTON_DELIM;
98         if (c == ':')
99                 return IN6PTON_COLON_MASK;
100         if (c == '.')
101                 return IN6PTON_DOT;
102         if (c >= '0' && c <= '9')
103                 return (IN6PTON_XDIGIT | IN6PTON_DIGIT| (c - '0'));
104         if (c >= 'a' && c <= 'f')
105                 return (IN6PTON_XDIGIT | (c - 'a' + 10));
106         if (c >= 'A' && c <= 'F')
107                 return (IN6PTON_XDIGIT | (c - 'A' + 10));
108         if (delim == -1)
109                 return IN6PTON_DELIM;
110         return IN6PTON_UNKNOWN;
111 }
112
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
166 EXPORT_SYMBOL(in4_pton);
167
168 int in6_pton(const char *src, int srclen,
169              u8 *dst,
170              int delim, const char **end)
171 {
172         const char *s, *tok = NULL;
173         u8 *d, *dc = NULL;
174         u8 dbuf[16];
175         int ret = 0;
176         int i;
177         int state = IN6PTON_COLON_1_2 | IN6PTON_XDIGIT | IN6PTON_NULL;
178         int w = 0;
179
180         memset(dbuf, 0, sizeof(dbuf));
181
182         s = src;
183         d = dbuf;
184         if (srclen < 0)
185                 srclen = strlen(src);
186
187         while (1) {
188                 int c;
189
190                 c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
191                 if (!(c & state))
192                         goto out;
193                 if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
194                         /* process one 16-bit word */
195                         if (!(state & IN6PTON_NULL)) {
196                                 *d++ = (w >> 8) & 0xff;
197                                 *d++ = w & 0xff;
198                         }
199                         w = 0;
200                         if (c & IN6PTON_DELIM) {
201                                 /* We've processed last word */
202                                 break;
203                         }
204                         /*
205                          * COLON_1 => XDIGIT
206                          * COLON_2 => XDIGIT|DELIM
207                          * COLON_1_2 => COLON_2
208                          */
209                         switch (state & IN6PTON_COLON_MASK) {
210                         case IN6PTON_COLON_2:
211                                 dc = d;
212                                 state = IN6PTON_XDIGIT | IN6PTON_DELIM;
213                                 if (dc - dbuf >= sizeof(dbuf))
214                                         state |= IN6PTON_NULL;
215                                 break;
216                         case IN6PTON_COLON_1|IN6PTON_COLON_1_2:
217                                 state = IN6PTON_XDIGIT | IN6PTON_COLON_2;
218                                 break;
219                         case IN6PTON_COLON_1:
220                                 state = IN6PTON_XDIGIT;
221                                 break;
222                         case IN6PTON_COLON_1_2:
223                                 state = IN6PTON_COLON_2;
224                                 break;
225                         default:
226                                 state = 0;
227                         }
228                         tok = s + 1;
229                         goto cont;
230                 }
231
232                 if (c & IN6PTON_DOT) {
233                         ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s);
234                         if (ret > 0) {
235                                 d += 4;
236                                 break;
237                         }
238                         goto out;
239                 }
240
241                 w = (w << 4) | (0xff & c);
242                 state = IN6PTON_COLON_1 | IN6PTON_DELIM;
243                 if (!(w & 0xf000)) {
244                         state |= IN6PTON_XDIGIT;
245                 }
246                 if (!dc && d + 2 < dbuf + sizeof(dbuf)) {
247                         state |= IN6PTON_COLON_1_2;
248                         state &= ~IN6PTON_DELIM;
249                 }
250                 if (d + 2 >= dbuf + sizeof(dbuf)) {
251                         state &= ~(IN6PTON_COLON_1|IN6PTON_COLON_1_2);
252                 }
253 cont:
254                 if ((dc && d + 4 < dbuf + sizeof(dbuf)) ||
255                     d + 4 == dbuf + sizeof(dbuf)) {
256                         state |= IN6PTON_DOT;
257                 }
258                 if (d >= dbuf + sizeof(dbuf)) {
259                         state &= ~(IN6PTON_XDIGIT|IN6PTON_COLON_MASK);
260                 }
261                 s++;
262                 srclen--;
263         }
264
265         i = 15; d--;
266
267         if (dc) {
268                 while(d >= dc)
269                         dst[i--] = *d--;
270                 while(i >= dc - dbuf)
271                         dst[i--] = 0;
272                 while(i >= 0)
273                         dst[i--] = *d--;
274         } else
275                 memcpy(dst, dbuf, sizeof(dbuf));
276
277         ret = 1;
278 out:
279         if (end)
280                 *end = s;
281         return ret;
282 }
283
284 EXPORT_SYMBOL(in6_pton);
285
286 void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
287                               __be32 from, __be32 to, int pseudohdr)
288 {
289         __be32 diff[] = { ~from, to };
290         if (skb->ip_summed != CHECKSUM_PARTIAL) {
291                 *sum = csum_fold(csum_partial(diff, sizeof(diff),
292                                 ~csum_unfold(*sum)));
293                 if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
294                         skb->csum = ~csum_partial(diff, sizeof(diff),
295                                                 ~skb->csum);
296         } else if (pseudohdr)
297                 *sum = ~csum_fold(csum_partial(diff, sizeof(diff),
298                                 csum_unfold(*sum)));
299 }
300 EXPORT_SYMBOL(inet_proto_csum_replace4);