[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 <net/net_ratelimit.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);

int mac_pton(const char *s, u8 *mac)
{
	int i;

	/* XX:XX:XX:XX:XX:XX */
	if (strlen(s) < 3 * ETH_ALEN - 1)
		return 0;

	/* Don't dirty result unless string is valid MAC. */
	for (i = 0; i < ETH_ALEN; i++) {
		if (!strchr("0123456789abcdefABCDEF", s[i * 3]))
			return 0;
		if (!strchr("0123456789abcdefABCDEF", s[i * 3 + 1]))
			return 0;
		if (i != ETH_ALEN - 1 && s[i * 3 + 2] != ':')
			return 0;
	}
	for (i = 0; i < ETH_ALEN; i++) {
		mac[i] = (hex_to_bin(s[i * 3]) << 4) | hex_to_bin(s[i * 3 + 1]);
	}
	return 1;
}
EXPORT_SYMBOL(mac_pton);
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>
c5c177b4	30	#include <net/net_ratelimit.h>
1da177e4	31
5e43db77	32	#include <asm/byteorder.h>
1da177e4 LT	33	#include <asm/system.h>
	34	#include <asm/uaccess.h>
	35
6dea649a	36	int net_msg_warn __read_mostly = 1;
a2a316fd	37	EXPORT_SYMBOL(net_msg_warn);
1da177e4	38
717115e1	39	DEFINE_RATELIMIT_STATE(net_ratelimit_state, 5 * HZ, 10);
4ec93edb	40	/*
1da177e4	41	* All net warning printk()s should be guarded by this function.
4ec93edb	42	*/
1da177e4 LT	43	int net_ratelimit(void)
1da177e4 LT	44	{
717115e1	45	return __ratelimit(&net_ratelimit_state);
1da177e4	46	}
1da177e4	47	EXPORT_SYMBOL(net_ratelimit);
5e43db77 MM	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
a2167dc6	55	__be32 in_aton(const char *str)
5e43db77 MM	56	{
	57	unsigned long l;
	58	unsigned int val;
	59	int i;
	60
	61	l = 0;
	62	for (i = 0; i < 4; i++)
	63	{
	64	l <<= 8;
	65	if (*str != '\0')
	66	{
	67	val = 0;
1e2e5659	68	while (str != '\0' && str != '.' && *str != '\n')
5e43db77 MM	69	{
	70	val *= 10;
	71	val += *str - '0';
	72	str++;
	73	}
	74	l \|= val;
	75	if (*str != '\0')
	76	str++;
	77	}
	78	}
a02cec21	79	return htonl(l);
5e43db77	80	}
5e43db77	81	EXPORT_SYMBOL(in_aton);
1aaec67f YH	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
9a7c9337	94	static inline int xdigit2bin(char c, int delim)
1aaec67f	95	{
82fd5b5d AS	96	int val;
82fd5b5d AS	97
1aaec67f YH	98	if (c == delim \|\| c == '\0')
	99	return IN6PTON_DELIM;
	100	if (c == ':')
	101	return IN6PTON_COLON_MASK;
	102	if (c == '.')
	103	return IN6PTON_DOT;
82fd5b5d AS	104
	105	val = hex_to_bin(c);
	106	if (val >= 0)
	107	return val \| IN6PTON_XDIGIT \| (val < 10 ? IN6PTON_DIGIT : 0);
	108
9a7c9337 PM	109	if (delim == -1)
9a7c9337 PM	110	return IN6PTON_DELIM;
1aaec67f YH	111	return IN6PTON_UNKNOWN;
	112	}
	113
	114	int in4_pton(const char *src, int srclen,
	115	u8 *dst,
9a7c9337	116	int delim, const char **end)
1aaec67f YH	117	{
	118	const char *s;
	119	u8 *d;
	120	u8 dbuf[4];
	121	int ret = 0;
	122	int i;
	123	int w = 0;
	124
	125	if (srclen < 0)
	126	srclen = strlen(src);
	127	s = src;
	128	d = dbuf;
	129	i = 0;
	130	while(1) {
	131	int c;
	132	c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
83f03fa5	133	if (!(c & (IN6PTON_DIGIT \| IN6PTON_DOT \| IN6PTON_DELIM \| IN6PTON_COLON_MASK))) {
1aaec67f YH	134	goto out;
1aaec67f YH	135	}
83f03fa5	136	if (c & (IN6PTON_DOT \| IN6PTON_DELIM \| IN6PTON_COLON_MASK)) {
1aaec67f YH	137	if (w == 0)
	138	goto out;
	139	*d++ = w & 0xff;
	140	w = 0;
	141	i++;
83f03fa5	142	if (c & (IN6PTON_DELIM \| IN6PTON_COLON_MASK)) {
1aaec67f YH	143	if (i != 4)
	144	goto out;
	145	break;
	146	}
	147	goto cont;
	148	}
	149	w = (w * 10) + c;
	150	if ((w & 0xffff) > 255) {
	151	goto out;
	152	}
	153	cont:
	154	if (i >= 4)
	155	goto out;
	156	s++;
	157	srclen--;
	158	}
	159	ret = 1;
	160	memcpy(dst, dbuf, sizeof(dbuf));
	161	out:
	162	if (end)
	163	*end = s;
	164	return ret;
	165	}
1aaec67f YH	166	EXPORT_SYMBOL(in4_pton);
	167
	168	int in6_pton(const char *src, int srclen,
	169	u8 *dst,
9a7c9337	170	int delim, const char **end)
1aaec67f YH	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
1aaec67f YH	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	}
1aaec67f	283	EXPORT_SYMBOL(in6_pton);
a99a00cf PM	284
	285	void inet_proto_csum_replace4(__sum16 sum, struct sk_buff skb,
	286	__be32 from, __be32 to, int pseudohdr)
	287	{
	288	__be32 diff[] = { ~from, to };
	289	if (skb->ip_summed != CHECKSUM_PARTIAL) {
	290	*sum = csum_fold(csum_partial(diff, sizeof(diff),
	291	~csum_unfold(*sum)));
	292	if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
	293	skb->csum = ~csum_partial(diff, sizeof(diff),
	294	~skb->csum);
	295	} else if (pseudohdr)
	296	*sum = ~csum_fold(csum_partial(diff, sizeof(diff),
	297	csum_unfold(*sum)));
	298	}
	299	EXPORT_SYMBOL(inet_proto_csum_replace4);
4940fc88 AD	300
	301	int mac_pton(const char s, u8 mac)
	302	{
	303	int i;
	304
	305	/* XX:XX:XX:XX:XX:XX */
	306	if (strlen(s) < 3 * ETH_ALEN - 1)
	307	return 0;
	308
	309	/* Don't dirty result unless string is valid MAC. */
	310	for (i = 0; i < ETH_ALEN; i++) {
	311	if (!strchr("0123456789abcdefABCDEF", s[i * 3]))
	312	return 0;
	313	if (!strchr("0123456789abcdefABCDEF", s[i * 3 + 1]))
	314	return 0;
	315	if (i != ETH_ALEN - 1 && s[i * 3 + 2] != ':')
	316	return 0;
	317	}
	318	for (i = 0; i < ETH_ALEN; i++) {
	319	mac[i] = (hex_to_bin(s[i * 3]) << 4) \| hex_to_bin(s[i * 3 + 1]);
	320	}
	321	return 1;
	322	}
	323	EXPORT_SYMBOL(mac_pton);