[NET]: Unexport sysctl_{r,w}mem_max.
[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/random.h>
26 #include <linux/percpu.h>
27 #include <linux/init.h>
28 #include <net/sock.h>
29
30 #include <asm/byteorder.h>
31 #include <asm/system.h>
32 #include <asm/uaccess.h>
33
34 int net_msg_cost __read_mostly = 5*HZ;
35 int net_msg_burst __read_mostly = 10;
36 int net_msg_warn __read_mostly = 1;
37 EXPORT_SYMBOL(net_msg_warn);
38
39 /*
40  * All net warning printk()s should be guarded by this function.
41  */
42 int net_ratelimit(void)
43 {
44         return __printk_ratelimit(net_msg_cost, net_msg_burst);
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 digit2bin(char c, int delim)
95 {
96         if (c == delim || c == '\0')
97                 return IN6PTON_DELIM;
98         if (c == '.')
99                 return IN6PTON_DOT;
100         if (c >= '0' && c <= '9')
101                 return (IN6PTON_DIGIT | (c - '0'));
102         return IN6PTON_UNKNOWN;
103 }
104
105 static inline int xdigit2bin(char c, int delim)
106 {
107         if (c == delim || c == '\0')
108                 return IN6PTON_DELIM;
109         if (c == ':')
110                 return IN6PTON_COLON_MASK;
111         if (c == '.')
112                 return IN6PTON_DOT;
113         if (c >= '0' && c <= '9')
114                 return (IN6PTON_XDIGIT | IN6PTON_DIGIT| (c - '0'));
115         if (c >= 'a' && c <= 'f')
116                 return (IN6PTON_XDIGIT | (c - 'a' + 10));
117         if (c >= 'A' && c <= 'F')
118                 return (IN6PTON_XDIGIT | (c - 'A' + 10));
119         if (delim == -1)
120                 return IN6PTON_DELIM;
121         return IN6PTON_UNKNOWN;
122 }
123
124 int in4_pton(const char *src, int srclen,
125              u8 *dst,
126              int delim, const char **end)
127 {
128         const char *s;
129         u8 *d;
130         u8 dbuf[4];
131         int ret = 0;
132         int i;
133         int w = 0;
134
135         if (srclen < 0)
136                 srclen = strlen(src);
137         s = src;
138         d = dbuf;
139         i = 0;
140         while(1) {
141                 int c;
142                 c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
143                 if (!(c & (IN6PTON_DIGIT | IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK))) {
144                         goto out;
145                 }
146                 if (c & (IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
147                         if (w == 0)
148                                 goto out;
149                         *d++ = w & 0xff;
150                         w = 0;
151                         i++;
152                         if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
153                                 if (i != 4)
154                                         goto out;
155                                 break;
156                         }
157                         goto cont;
158                 }
159                 w = (w * 10) + c;
160                 if ((w & 0xffff) > 255) {
161                         goto out;
162                 }
163 cont:
164                 if (i >= 4)
165                         goto out;
166                 s++;
167                 srclen--;
168         }
169         ret = 1;
170         memcpy(dst, dbuf, sizeof(dbuf));
171 out:
172         if (end)
173                 *end = s;
174         return ret;
175 }
176
177 EXPORT_SYMBOL(in4_pton);
178
179 int in6_pton(const char *src, int srclen,
180              u8 *dst,
181              int delim, const char **end)
182 {
183         const char *s, *tok = NULL;
184         u8 *d, *dc = NULL;
185         u8 dbuf[16];
186         int ret = 0;
187         int i;
188         int state = IN6PTON_COLON_1_2 | IN6PTON_XDIGIT | IN6PTON_NULL;
189         int w = 0;
190
191         memset(dbuf, 0, sizeof(dbuf));
192
193         s = src;
194         d = dbuf;
195         if (srclen < 0)
196                 srclen = strlen(src);
197
198         while (1) {
199                 int c;
200
201                 c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
202                 if (!(c & state))
203                         goto out;
204                 if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
205                         /* process one 16-bit word */
206                         if (!(state & IN6PTON_NULL)) {
207                                 *d++ = (w >> 8) & 0xff;
208                                 *d++ = w & 0xff;
209                         }
210                         w = 0;
211                         if (c & IN6PTON_DELIM) {
212                                 /* We've processed last word */
213                                 break;
214                         }
215                         /*
216                          * COLON_1 => XDIGIT
217                          * COLON_2 => XDIGIT|DELIM
218                          * COLON_1_2 => COLON_2
219                          */
220                         switch (state & IN6PTON_COLON_MASK) {
221                         case IN6PTON_COLON_2:
222                                 dc = d;
223                                 state = IN6PTON_XDIGIT | IN6PTON_DELIM;
224                                 if (dc - dbuf >= sizeof(dbuf))
225                                         state |= IN6PTON_NULL;
226                                 break;
227                         case IN6PTON_COLON_1|IN6PTON_COLON_1_2:
228                                 state = IN6PTON_XDIGIT | IN6PTON_COLON_2;
229                                 break;
230                         case IN6PTON_COLON_1:
231                                 state = IN6PTON_XDIGIT;
232                                 break;
233                         case IN6PTON_COLON_1_2:
234                                 state = IN6PTON_COLON_2;
235                                 break;
236                         default:
237                                 state = 0;
238                         }
239                         tok = s + 1;
240                         goto cont;
241                 }
242
243                 if (c & IN6PTON_DOT) {
244                         ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s);
245                         if (ret > 0) {
246                                 d += 4;
247                                 break;
248                         }
249                         goto out;
250                 }
251
252                 w = (w << 4) | (0xff & c);
253                 state = IN6PTON_COLON_1 | IN6PTON_DELIM;
254                 if (!(w & 0xf000)) {
255                         state |= IN6PTON_XDIGIT;
256                 }
257                 if (!dc && d + 2 < dbuf + sizeof(dbuf)) {
258                         state |= IN6PTON_COLON_1_2;
259                         state &= ~IN6PTON_DELIM;
260                 }
261                 if (d + 2 >= dbuf + sizeof(dbuf)) {
262                         state &= ~(IN6PTON_COLON_1|IN6PTON_COLON_1_2);
263                 }
264 cont:
265                 if ((dc && d + 4 < dbuf + sizeof(dbuf)) ||
266                     d + 4 == dbuf + sizeof(dbuf)) {
267                         state |= IN6PTON_DOT;
268                 }
269                 if (d >= dbuf + sizeof(dbuf)) {
270                         state &= ~(IN6PTON_XDIGIT|IN6PTON_COLON_MASK);
271                 }
272                 s++;
273                 srclen--;
274         }
275
276         i = 15; d--;
277
278         if (dc) {
279                 while(d >= dc)
280                         dst[i--] = *d--;
281                 while(i >= dc - dbuf)
282                         dst[i--] = 0;
283                 while(i >= 0)
284                         dst[i--] = *d--;
285         } else
286                 memcpy(dst, dbuf, sizeof(dbuf));
287
288         ret = 1;
289 out:
290         if (end)
291                 *end = s;
292         return ret;
293 }
294
295 EXPORT_SYMBOL(in6_pton);