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
29#include <asm/byteorder.h>
30#include <asm/system.h>
31#include <asm/uaccess.h>
32
33int net_msg_cost __read_mostly = 5*HZ;
34int net_msg_burst __read_mostly = 10;
35int net_msg_warn __read_mostly = 1;
36EXPORT_SYMBOL(net_msg_warn);
37
38/*
39 * All net warning printk()s should be guarded by this function.
40 */
41int net_ratelimit(void)
42{
43	return __printk_ratelimit(net_msg_cost, net_msg_burst);
44}
45EXPORT_SYMBOL(net_ratelimit);
46
47/*
48 * Convert an ASCII string to binary IP.
49 * This is outside of net/ipv4/ because various code that uses IP addresses
50 * is otherwise not dependent on the TCP/IP stack.
51 */
52
53__be32 in_aton(const char *str)
54{
55	unsigned long l;
56	unsigned int val;
57	int i;
58
59	l = 0;
60	for (i = 0; i < 4; i++)
61	{
62		l <<= 8;
63		if (*str != '\0')
64		{
65			val = 0;
66			while (*str != '\0' && *str != '.' && *str != '\n')
67			{
68				val *= 10;
69				val += *str - '0';
70				str++;
71			}
72			l |= val;
73			if (*str != '\0')
74				str++;
75		}
76	}
77	return(htonl(l));
78}
79
80EXPORT_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
93static inline int digit2bin(char c, int delim)
94{
95	if (c == delim || c == '\0')
96		return IN6PTON_DELIM;
97	if (c == '.')
98		return IN6PTON_DOT;
99	if (c >= '0' && c <= '9')
100		return (IN6PTON_DIGIT | (c - '0'));
101	return IN6PTON_UNKNOWN;
102}
103
104static inline int xdigit2bin(char c, int delim)
105{
106	if (c == delim || c == '\0')
107		return IN6PTON_DELIM;
108	if (c == ':')
109		return IN6PTON_COLON_MASK;
110	if (c == '.')
111		return IN6PTON_DOT;
112	if (c >= '0' && c <= '9')
113		return (IN6PTON_XDIGIT | IN6PTON_DIGIT| (c - '0'));
114	if (c >= 'a' && c <= 'f')
115		return (IN6PTON_XDIGIT | (c - 'a' + 10));
116	if (c >= 'A' && c <= 'F')
117		return (IN6PTON_XDIGIT | (c - 'A' + 10));
118	if (delim == -1)
119		return IN6PTON_DELIM;
120	return IN6PTON_UNKNOWN;
121}
122
123int 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		}
162cont:
163		if (i >= 4)
164			goto out;
165		s++;
166		srclen--;
167	}
168	ret = 1;
169	memcpy(dst, dbuf, sizeof(dbuf));
170out:
171	if (end)
172		*end = s;
173	return ret;
174}
175
176EXPORT_SYMBOL(in4_pton);
177
178int in6_pton(const char *src, int srclen,
179	     u8 *dst,
180	     int delim, const char **end)
181{
182	const char *s, *tok = NULL;
183	u8 *d, *dc = NULL;
184	u8 dbuf[16];
185	int ret = 0;
186	int i;
187	int state = IN6PTON_COLON_1_2 | IN6PTON_XDIGIT | IN6PTON_NULL;
188	int w = 0;
189
190	memset(dbuf, 0, sizeof(dbuf));
191
192	s = src;
193	d = dbuf;
194	if (srclen < 0)
195		srclen = strlen(src);
196
197	while (1) {
198		int c;
199
200		c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
201		if (!(c & state))
202			goto out;
203		if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
204			/* process one 16-bit word */
205			if (!(state & IN6PTON_NULL)) {
206				*d++ = (w >> 8) & 0xff;
207				*d++ = w & 0xff;
208			}
209			w = 0;
210			if (c & IN6PTON_DELIM) {
211				/* We've processed last word */
212				break;
213			}
214			/*
215			 * COLON_1 => XDIGIT
216			 * COLON_2 => XDIGIT|DELIM
217			 * COLON_1_2 => COLON_2
218			 */
219			switch (state & IN6PTON_COLON_MASK) {
220			case IN6PTON_COLON_2:
221				dc = d;
222				state = IN6PTON_XDIGIT | IN6PTON_DELIM;
223				if (dc - dbuf >= sizeof(dbuf))
224					state |= IN6PTON_NULL;
225				break;
226			case IN6PTON_COLON_1|IN6PTON_COLON_1_2:
227				state = IN6PTON_XDIGIT | IN6PTON_COLON_2;
228				break;
229			case IN6PTON_COLON_1:
230				state = IN6PTON_XDIGIT;
231				break;
232			case IN6PTON_COLON_1_2:
233				state = IN6PTON_COLON_2;
234				break;
235			default:
236				state = 0;
237			}
238			tok = s + 1;
239			goto cont;
240		}
241
242		if (c & IN6PTON_DOT) {
243			ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s);
244			if (ret > 0) {
245				d += 4;
246				break;
247			}
248			goto out;
249		}
250
251		w = (w << 4) | (0xff & c);
252		state = IN6PTON_COLON_1 | IN6PTON_DELIM;
253		if (!(w & 0xf000)) {
254			state |= IN6PTON_XDIGIT;
255		}
256		if (!dc && d + 2 < dbuf + sizeof(dbuf)) {
257			state |= IN6PTON_COLON_1_2;
258			state &= ~IN6PTON_DELIM;
259		}
260		if (d + 2 >= dbuf + sizeof(dbuf)) {
261			state &= ~(IN6PTON_COLON_1|IN6PTON_COLON_1_2);
262		}
263cont:
264		if ((dc && d + 4 < dbuf + sizeof(dbuf)) ||
265		    d + 4 == dbuf + sizeof(dbuf)) {
266			state |= IN6PTON_DOT;
267		}
268		if (d >= dbuf + sizeof(dbuf)) {
269			state &= ~(IN6PTON_XDIGIT|IN6PTON_COLON_MASK);
270		}
271		s++;
272		srclen--;
273	}
274
275	i = 15; d--;
276
277	if (dc) {
278		while(d >= dc)
279			dst[i--] = *d--;
280		while(i >= dc - dbuf)
281			dst[i--] = 0;
282		while(i >= 0)
283			dst[i--] = *d--;
284	} else
285		memcpy(dst, dbuf, sizeof(dbuf));
286
287	ret = 1;
288out:
289	if (end)
290		*end = s;
291	return ret;
292}
293
294EXPORT_SYMBOL(in6_pton);
295