[linux.git] / net / core / utils.c

/*
 *	Generic address resultion entity
 *
 *	Authors:
 *	net_random Alan Cox
 *	net_ratelimit Andi Kleen
 *	in{4,6}_pton YOSHIFUJI Hideaki, Copyright (C)2006 USAGI/WIDE Project
 *
 *	Created by Alexey Kuznetsov <[email protected]>
 *
 *	This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/inet.h>
#include <linux/mm.h>
#include <linux/net.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/percpu.h>
#include <linux/init.h>
#include <linux/ratelimit.h>

#include <net/sock.h>

#include <asm/byteorder.h>
#include <asm/system.h>
#include <asm/uaccess.h>

int net_msg_warn __read_mostly = 1;
EXPORT_SYMBOL(net_msg_warn);

DEFINE_RATELIMIT_STATE(net_ratelimit_state, 5 * HZ, 10);
/*
 * All net warning printk()s should be guarded by this function.
 */
int net_ratelimit(void)
{
	return __ratelimit(&net_ratelimit_state);
}
EXPORT_SYMBOL(net_ratelimit);

/*
 * Convert an ASCII string to binary IP.
 * This is outside of net/ipv4/ because various code that uses IP addresses
 * is otherwise not dependent on the TCP/IP stack.
 */

__be32 in_aton(const char *str)
{
	unsigned long l;
	unsigned int val;
	int i;

	l = 0;
	for (i = 0; i < 4; i++)
	{
		l <<= 8;
		if (*str != '\0')
		{
			val = 0;
			while (*str != '\0' && *str != '.' && *str != '\n')
			{
				val *= 10;
				val += *str - '0';
				str++;
			}
			l |= val;
			if (*str != '\0')
				str++;
		}
	}
	return htonl(l);
}
EXPORT_SYMBOL(in_aton);

#define IN6PTON_XDIGIT		0x00010000
#define IN6PTON_DIGIT		0x00020000
#define IN6PTON_COLON_MASK	0x00700000
#define IN6PTON_COLON_1		0x00100000	/* single : requested */
#define IN6PTON_COLON_2		0x00200000	/* second : requested */
#define IN6PTON_COLON_1_2	0x00400000	/* :: requested */
#define IN6PTON_DOT		0x00800000	/* . */
#define IN6PTON_DELIM		0x10000000
#define IN6PTON_NULL		0x20000000	/* first/tail */
#define IN6PTON_UNKNOWN		0x40000000

static inline int xdigit2bin(char c, int delim)
{
	int val;

	if (c == delim || c == '\0')
		return IN6PTON_DELIM;
	if (c == ':')
		return IN6PTON_COLON_MASK;
	if (c == '.')
		return IN6PTON_DOT;

	val = hex_to_bin(c);
	if (val >= 0)
		return val | IN6PTON_XDIGIT | (val < 10 ? IN6PTON_DIGIT : 0);

	if (delim == -1)
		return IN6PTON_DELIM;
	return IN6PTON_UNKNOWN;
}

int in4_pton(const char *src, int srclen,
	     u8 *dst,
	     int delim, const char **end)
{
	const char *s;
	u8 *d;
	u8 dbuf[4];
	int ret = 0;
	int i;
	int w = 0;

	if (srclen < 0)
		srclen = strlen(src);
	s = src;
	d = dbuf;
	i = 0;
	while(1) {
		int c;
		c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
		if (!(c & (IN6PTON_DIGIT | IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK))) {
			goto out;
		}
		if (c & (IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
			if (w == 0)
				goto out;
			*d++ = w & 0xff;
			w = 0;
			i++;
			if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
				if (i != 4)
					goto out;
				break;
			}
			goto cont;
		}
		w = (w * 10) + c;
		if ((w & 0xffff) > 255) {
			goto out;
		}
cont:
		if (i >= 4)
			goto out;
		s++;
		srclen--;
	}
	ret = 1;
	memcpy(dst, dbuf, sizeof(dbuf));
out:
	if (end)
		*end = s;
	return ret;
}
EXPORT_SYMBOL(in4_pton);

int in6_pton(const char *src, int srclen,
	     u8 *dst,
	     int delim, const char **end)
{
	const char *s, *tok = NULL;
	u8 *d, *dc = NULL;
	u8 dbuf[16];
	int ret = 0;
	int i;
	int state = IN6PTON_COLON_1_2 | IN6PTON_XDIGIT | IN6PTON_NULL;
	int w = 0;

	memset(dbuf, 0, sizeof(dbuf));

	s = src;
	d = dbuf;
	if (srclen < 0)
		srclen = strlen(src);

	while (1) {
		int c;

		c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
		if (!(c & state))
			goto out;
		if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
			/* process one 16-bit word */
			if (!(state & IN6PTON_NULL)) {
				*d++ = (w >> 8) & 0xff;
				*d++ = w & 0xff;
			}
			w = 0;
			if (c & IN6PTON_DELIM) {
				/* We've processed last word */
				break;
			}
			/*
			 * COLON_1 => XDIGIT
			 * COLON_2 => XDIGIT|DELIM
			 * COLON_1_2 => COLON_2
			 */
			switch (state & IN6PTON_COLON_MASK) {
			case IN6PTON_COLON_2:
				dc = d;
				state = IN6PTON_XDIGIT | IN6PTON_DELIM;
				if (dc - dbuf >= sizeof(dbuf))
					state |= IN6PTON_NULL;
				break;
			case IN6PTON_COLON_1|IN6PTON_COLON_1_2:
				state = IN6PTON_XDIGIT | IN6PTON_COLON_2;
				break;
			case IN6PTON_COLON_1:
				state = IN6PTON_XDIGIT;
				break;
			case IN6PTON_COLON_1_2:
				state = IN6PTON_COLON_2;
				break;
			default:
				state = 0;
			}
			tok = s + 1;
			goto cont;
		}

		if (c & IN6PTON_DOT) {
			ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s);
			if (ret > 0) {
				d += 4;
				break;
			}
			goto out;
		}

		w = (w << 4) | (0xff & c);
		state = IN6PTON_COLON_1 | IN6PTON_DELIM;
		if (!(w & 0xf000)) {
			state |= IN6PTON_XDIGIT;
		}
		if (!dc && d + 2 < dbuf + sizeof(dbuf)) {
			state |= IN6PTON_COLON_1_2;
			state &= ~IN6PTON_DELIM;
		}
		if (d + 2 >= dbuf + sizeof(dbuf)) {
			state &= ~(IN6PTON_COLON_1|IN6PTON_COLON_1_2);
		}
cont:
		if ((dc && d + 4 < dbuf + sizeof(dbuf)) ||
		    d + 4 == dbuf + sizeof(dbuf)) {
			state |= IN6PTON_DOT;
		}
		if (d >= dbuf + sizeof(dbuf)) {
			state &= ~(IN6PTON_XDIGIT|IN6PTON_COLON_MASK);
		}
		s++;
		srclen--;
	}

	i = 15; d--;

	if (dc) {
		while(d >= dc)
			dst[i--] = *d--;
		while(i >= dc - dbuf)
			dst[i--] = 0;
		while(i >= 0)
			dst[i--] = *d--;
	} else
		memcpy(dst, dbuf, sizeof(dbuf));

	ret = 1;
out:
	if (end)
		*end = s;
	return ret;
}
EXPORT_SYMBOL(in6_pton);

void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
			      __be32 from, __be32 to, int pseudohdr)
{
	__be32 diff[] = { ~from, to };
	if (skb->ip_summed != CHECKSUM_PARTIAL) {
		*sum = csum_fold(csum_partial(diff, sizeof(diff),
				~csum_unfold(*sum)));
		if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
			skb->csum = ~csum_partial(diff, sizeof(diff),
						~skb->csum);
	} else if (pseudohdr)
		*sum = ~csum_fold(csum_partial(diff, sizeof(diff),
				csum_unfold(*sum)));
}
EXPORT_SYMBOL(inet_proto_csum_replace4);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Generic address resultion entity
	3	*
	4	* Authors:
	5	* net_random Alan Cox
75b31c33	6	* net_ratelimit Andi Kleen
1aaec67f	7	* in{4,6}_pton YOSHIFUJI Hideaki, Copyright (C)2006 USAGI/WIDE Project
1da177e4 LT	8	*
	9	* Created by Alexey Kuznetsov <[email protected]>
	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>
20380731	20	#include <linux/inet.h>
1da177e4	21	#include <linux/mm.h>
20380731	22	#include <linux/net.h>
1da177e4 LT	23	#include <linux/string.h>
1da177e4 LT	24	#include <linux/types.h>
1da177e4 LT	25	#include <linux/percpu.h>
1da177e4 LT	26	#include <linux/init.h>
3fff4c42 IM	27	#include <linux/ratelimit.h>
3fff4c42 IM	28
14ae8566	29	#include <net/sock.h>
1da177e4	30
5e43db77	31	#include <asm/byteorder.h>
1da177e4 LT	32	#include <asm/system.h>
	33	#include <asm/uaccess.h>
	34
6dea649a	35	int net_msg_warn __read_mostly = 1;
a2a316fd	36	EXPORT_SYMBOL(net_msg_warn);
1da177e4	37
717115e1	38	DEFINE_RATELIMIT_STATE(net_ratelimit_state, 5 * HZ, 10);
4ec93edb	39	/*
1da177e4	40	* All net warning printk()s should be guarded by this function.
4ec93edb	41	*/
1da177e4 LT	42	int net_ratelimit(void)
1da177e4 LT	43	{
717115e1	44	return __ratelimit(&net_ratelimit_state);
1da177e4	45	}
1da177e4	46	EXPORT_SYMBOL(net_ratelimit);
5e43db77 MM	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
a2167dc6	54	__be32 in_aton(const char *str)
5e43db77 MM	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;
1e2e5659	67	while (str != '\0' && str != '.' && *str != '\n')
5e43db77 MM	68	{
	69	val *= 10;
	70	val += *str - '0';
	71	str++;
	72	}
	73	l \|= val;
	74	if (*str != '\0')
	75	str++;
	76	}
	77	}
a02cec21	78	return htonl(l);
5e43db77	79	}
5e43db77	80	EXPORT_SYMBOL(in_aton);
1aaec67f YH	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
9a7c9337	93	static inline int xdigit2bin(char c, int delim)
1aaec67f	94	{
82fd5b5d AS	95	int val;
82fd5b5d AS	96
1aaec67f YH	97	if (c == delim \|\| c == '\0')
	98	return IN6PTON_DELIM;
	99	if (c == ':')
	100	return IN6PTON_COLON_MASK;
	101	if (c == '.')
	102	return IN6PTON_DOT;
82fd5b5d AS	103
	104	val = hex_to_bin(c);
	105	if (val >= 0)
	106	return val \| IN6PTON_XDIGIT \| (val < 10 ? IN6PTON_DIGIT : 0);
	107
9a7c9337 PM	108	if (delim == -1)
9a7c9337 PM	109	return IN6PTON_DELIM;
1aaec67f YH	110	return IN6PTON_UNKNOWN;
	111	}
	112
	113	int in4_pton(const char *src, int srclen,
	114	u8 *dst,
9a7c9337	115	int delim, const char **end)
1aaec67f YH	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);
83f03fa5	132	if (!(c & (IN6PTON_DIGIT \| IN6PTON_DOT \| IN6PTON_DELIM \| IN6PTON_COLON_MASK))) {
1aaec67f YH	133	goto out;
1aaec67f YH	134	}
83f03fa5	135	if (c & (IN6PTON_DOT \| IN6PTON_DELIM \| IN6PTON_COLON_MASK)) {
1aaec67f YH	136	if (w == 0)
	137	goto out;
	138	*d++ = w & 0xff;
	139	w = 0;
	140	i++;
83f03fa5	141	if (c & (IN6PTON_DELIM \| IN6PTON_COLON_MASK)) {
1aaec67f YH	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	}
1aaec67f YH	165	EXPORT_SYMBOL(in4_pton);
	166
	167	int in6_pton(const char *src, int srclen,
	168	u8 *dst,
9a7c9337	169	int delim, const char **end)
1aaec67f YH	170	{
	171	const char s, tok = NULL;
	172	u8 d, dc = NULL;
	173	u8 dbuf[16];
	174	int ret = 0;
	175	int i;
	176	int state = IN6PTON_COLON_1_2 \| IN6PTON_XDIGIT \| IN6PTON_NULL;
	177	int w = 0;
	178
	179	memset(dbuf, 0, sizeof(dbuf));
	180
	181	s = src;
	182	d = dbuf;
	183	if (srclen < 0)
	184	srclen = strlen(src);
	185
1aaec67f YH	186	while (1) {
	187	int c;
	188
	189	c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
	190	if (!(c & state))
	191	goto out;
	192	if (c & (IN6PTON_DELIM \| IN6PTON_COLON_MASK)) {
	193	/* process one 16-bit word */
	194	if (!(state & IN6PTON_NULL)) {
	195	*d++ = (w >> 8) & 0xff;
	196	*d++ = w & 0xff;
	197	}
	198	w = 0;
	199	if (c & IN6PTON_DELIM) {
	200	/* We've processed last word */
	201	break;
	202	}
	203	/*
	204	* COLON_1 => XDIGIT
	205	* COLON_2 => XDIGIT\|DELIM
	206	* COLON_1_2 => COLON_2
	207	*/
	208	switch (state & IN6PTON_COLON_MASK) {
	209	case IN6PTON_COLON_2:
	210	dc = d;
	211	state = IN6PTON_XDIGIT \| IN6PTON_DELIM;
	212	if (dc - dbuf >= sizeof(dbuf))
	213	state \|= IN6PTON_NULL;
	214	break;
	215	case IN6PTON_COLON_1\|IN6PTON_COLON_1_2:
	216	state = IN6PTON_XDIGIT \| IN6PTON_COLON_2;
	217	break;
	218	case IN6PTON_COLON_1:
	219	state = IN6PTON_XDIGIT;
	220	break;
	221	case IN6PTON_COLON_1_2:
	222	state = IN6PTON_COLON_2;
	223	break;
	224	default:
	225	state = 0;
	226	}
	227	tok = s + 1;
	228	goto cont;
	229	}
	230
	231	if (c & IN6PTON_DOT) {
	232	ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s);
	233	if (ret > 0) {
	234	d += 4;
	235	break;
	236	}
	237	goto out;
	238	}
	239
	240	w = (w << 4) \| (0xff & c);
	241	state = IN6PTON_COLON_1 \| IN6PTON_DELIM;
	242	if (!(w & 0xf000)) {
	243	state \|= IN6PTON_XDIGIT;
	244	}
	245	if (!dc && d + 2 < dbuf + sizeof(dbuf)) {
	246	state \|= IN6PTON_COLON_1_2;
	247	state &= ~IN6PTON_DELIM;
	248	}
	249	if (d + 2 >= dbuf + sizeof(dbuf)) {
250	state &= ~(IN6PTON_COLON_1\|IN6PTON_COLON_1_2);
251	}
252	cont:
253	if ((dc && d + 4 < dbuf + sizeof(dbuf)) \|\|
254	d + 4 == dbuf + sizeof(dbuf)) {
255	state \|= IN6PTON_DOT;
256	}
257	if (d >= dbuf + sizeof(dbuf)) {
258	state &= ~(IN6PTON_XDIGIT\|IN6PTON_COLON_MASK);
259	}
260	s++;
261	srclen--;
262	}
263
264	i = 15; d--;
265
266	if (dc) {
267	while(d >= dc)
268	dst[i--] = *d--;
269	while(i >= dc - dbuf)
270	dst[i--] = 0;
271	while(i >= 0)
272	dst[i--] = *d--;
273	} else
274	memcpy(dst, dbuf, sizeof(dbuf));
275
276	ret = 1;
277	out:
278	if (end)
279	*end = s;
280	return ret;
281	}
1aaec67f	282	EXPORT_SYMBOL(in6_pton);
a99a00cf PM	283
	284	void inet_proto_csum_replace4(__sum16 sum, struct sk_buff skb,
	285	__be32 from, __be32 to, int pseudohdr)
	286	{
	287	__be32 diff[] = { ~from, to };
	288	if (skb->ip_summed != CHECKSUM_PARTIAL) {
	289	*sum = csum_fold(csum_partial(diff, sizeof(diff),
	290	~csum_unfold(*sum)));
	291	if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
	292	skb->csum = ~csum_partial(diff, sizeof(diff),
	293	~skb->csum);
	294	} else if (pseudohdr)
	295	*sum = ~csum_fold(csum_partial(diff, sizeof(diff),
	296	csum_unfold(*sum)));
	297	}
	298	EXPORT_SYMBOL(inet_proto_csum_replace4);