aio: don't include aio.h in sched.h
[linux-3.10.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/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  */
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
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
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  */
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  */
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
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
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
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);