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

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	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]>
 */

#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/ctype.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 <linux/socket.h>

#include <net/sock.h>
#include <net/net_ratelimit.h>
#include <net/ipv6.h>

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

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 int 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;
}

/**
 * in4_pton - convert an IPv4 address from literal to binary representation
 * @src: the start of the IPv4 address string
 * @srclen: the length of the string, -1 means strlen(src)
 * @dst: the binary (u8[4] array) representation of the IPv4 address
 * @delim: the delimiter of the IPv4 address in @src, -1 means no delimiter
 * @end: A pointer to the end of the parsed string will be placed here
 *
 * Return one on success, return zero when any error occurs
 * and @end will point to the end of the parsed string.
 *
 */
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);

/**
 * in6_pton - convert an IPv6 address from literal to binary representation
 * @src: the start of the IPv6 address string
 * @srclen: the length of the string, -1 means strlen(src)
 * @dst: the binary (u8[16] array) representation of the IPv6 address
 * @delim: the delimiter of the IPv6 address in @src, -1 means no delimiter
 * @end: A pointer to the end of the parsed string will be placed here
 *
 * Return one on success, return zero when any error occurs
 * and @end will point to the end of the parsed string.
 *
 */
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);

static int inet4_pton(const char *src, u16 port_num,
		struct sockaddr_storage *addr)
{
	struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
	int srclen = strlen(src);

	if (srclen > INET_ADDRSTRLEN)
		return -EINVAL;

	if (in4_pton(src, srclen, (u8 *)&addr4->sin_addr.s_addr,
		     '\n', NULL) == 0)
		return -EINVAL;

	addr4->sin_family = AF_INET;
	addr4->sin_port = htons(port_num);

	return 0;
}

static int inet6_pton(struct net *net, const char *src, u16 port_num,
		struct sockaddr_storage *addr)
{
	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
	const char *scope_delim;
	int srclen = strlen(src);

	if (srclen > INET6_ADDRSTRLEN)
		return -EINVAL;

	if (in6_pton(src, srclen, (u8 *)&addr6->sin6_addr.s6_addr,
		     '%', &scope_delim) == 0)
		return -EINVAL;

	if (ipv6_addr_type(&addr6->sin6_addr) & IPV6_ADDR_LINKLOCAL &&
	    src + srclen != scope_delim && *scope_delim == '%') {
		struct net_device *dev;
		char scope_id[16];
		size_t scope_len = min_t(size_t, sizeof(scope_id) - 1,
					 src + srclen - scope_delim - 1);

		memcpy(scope_id, scope_delim + 1, scope_len);
		scope_id[scope_len] = '\0';

		dev = dev_get_by_name(net, scope_id);
		if (dev) {
			addr6->sin6_scope_id = dev->ifindex;
			dev_put(dev);
		} else if (kstrtouint(scope_id, 0, &addr6->sin6_scope_id)) {
			return -EINVAL;
		}
	}

	addr6->sin6_family = AF_INET6;
	addr6->sin6_port = htons(port_num);

	return 0;
}

/**
 * inet_pton_with_scope - convert an IPv4/IPv6 and port to socket address
 * @net: net namespace (used for scope handling)
 * @af: address family, AF_INET, AF_INET6 or AF_UNSPEC for either
 * @src: the start of the address string
 * @port: the start of the port string (or NULL for none)
 * @addr: output socket address
 *
 * Return zero on success, return errno when any error occurs.
 */
int inet_pton_with_scope(struct net *net, __kernel_sa_family_t af,
		const char *src, const char *port, struct sockaddr_storage *addr)
{
	u16 port_num;
	int ret = -EINVAL;

	if (port) {
		if (kstrtou16(port, 0, &port_num))
			return -EINVAL;
	} else {
		port_num = 0;
	}

	switch (af) {
	case AF_INET:
		ret = inet4_pton(src, port_num, addr);
		break;
	case AF_INET6:
		ret = inet6_pton(net, src, port_num, addr);
		break;
	case AF_UNSPEC:
		ret = inet4_pton(src, port_num, addr);
		if (ret)
			ret = inet6_pton(net, src, port_num, addr);
		break;
	default:
		pr_err("unexpected address family %d\n", af);
	}

	return ret;
}
EXPORT_SYMBOL(inet_pton_with_scope);

bool inet_addr_is_any(struct sockaddr *addr)
{
	if (addr->sa_family == AF_INET6) {
		struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)addr;
		const struct sockaddr_in6 in6_any =
			{ .sin6_addr = IN6ADDR_ANY_INIT };

		if (!memcmp(in6->sin6_addr.s6_addr,
			    in6_any.sin6_addr.s6_addr, 16))
			return true;
	} else if (addr->sa_family == AF_INET) {
		struct sockaddr_in *in = (struct sockaddr_in *)addr;

		if (in->sin_addr.s_addr == htonl(INADDR_ANY))
			return true;
	} else {
		pr_warn("unexpected address family %u\n", addr->sa_family);
	}

	return false;
}
EXPORT_SYMBOL(inet_addr_is_any);

void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
			      __be32 from, __be32 to, bool pseudohdr)
{
	if (skb->ip_summed != CHECKSUM_PARTIAL) {
		csum_replace4(sum, from, to);
		if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
			skb->csum = ~csum_add(csum_sub(~(skb->csum),
						       (__force __wsum)from),
					      (__force __wsum)to);
	} else if (pseudohdr)
		*sum = ~csum_fold(csum_add(csum_sub(csum_unfold(*sum),
						    (__force __wsum)from),
					   (__force __wsum)to));
}
EXPORT_SYMBOL(inet_proto_csum_replace4);

/**
 * inet_proto_csum_replace16 - update layer 4 header checksum field
 * @sum: Layer 4 header checksum field
 * @skb: sk_buff for the packet
 * @from: old IPv6 address
 * @to: new IPv6 address
 * @pseudohdr: True if layer 4 header checksum includes pseudoheader
 *
 * Update layer 4 header as per the update in IPv6 src/dst address.
 *
 * There is no need to update skb->csum in this function, because update in two
 * fields a.) IPv6 src/dst address and b.) L4 header checksum cancels each other
 * for skb->csum calculation. Whereas inet_proto_csum_replace4 function needs to
 * update skb->csum, because update in 3 fields a.) IPv4 src/dst address,
 * b.) IPv4 Header checksum and c.) L4 header checksum results in same diff as
 * L4 Header checksum for skb->csum calculation.
 */
void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb,
			       const __be32 *from, const __be32 *to,
			       bool pseudohdr)
{
	__be32 diff[] = {
		~from[0], ~from[1], ~from[2], ~from[3],
		to[0], to[1], to[2], to[3],
	};
	if (skb->ip_summed != CHECKSUM_PARTIAL) {
		*sum = csum_fold(csum_partial(diff, sizeof(diff),
				 ~csum_unfold(*sum)));
	} else if (pseudohdr)
		*sum = ~csum_fold(csum_partial(diff, sizeof(diff),
				  csum_unfold(*sum)));
}
EXPORT_SYMBOL(inet_proto_csum_replace16);

void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb,
				     __wsum diff, bool pseudohdr)
{
	if (skb->ip_summed != CHECKSUM_PARTIAL) {
		*sum = csum_fold(csum_add(diff, ~csum_unfold(*sum)));
		if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
			skb->csum = ~csum_add(diff, ~skb->csum);
	} else if (pseudohdr) {
		*sum = ~csum_fold(csum_add(diff, csum_unfold(*sum)));
	}
}
EXPORT_SYMBOL(inet_proto_csum_replace_by_diff);
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
	3	* Generic address resultion entity
	4	*
	5	* Authors:
	6	* net_random Alan Cox
75b31c33	7	* net_ratelimit Andi Kleen
1aaec67f	8	* in{4,6}_pton YOSHIFUJI Hideaki, Copyright (C)2006 USAGI/WIDE Project
1da177e4 LT	9	*
1da177e4 LT	10	* Created by Alexey Kuznetsov <[email protected]>
1da177e4 LT	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/jiffies.h>
	15	#include <linux/kernel.h>
5a048e3b	16	#include <linux/ctype.h>
20380731	17	#include <linux/inet.h>
1da177e4	18	#include <linux/mm.h>
20380731	19	#include <linux/net.h>
1da177e4 LT	20	#include <linux/string.h>
1da177e4 LT	21	#include <linux/types.h>
1da177e4 LT	22	#include <linux/percpu.h>
1da177e4 LT	23	#include <linux/init.h>
3fff4c42	24	#include <linux/ratelimit.h>
b1a951fe	25	#include <linux/socket.h>
3fff4c42	26
14ae8566	27	#include <net/sock.h>
c5c177b4	28	#include <net/net_ratelimit.h>
b1a951fe	29	#include <net/ipv6.h>
1da177e4	30
5e43db77	31	#include <asm/byteorder.h>
7c0f6ba6	32	#include <linux/uaccess.h>
1da177e4	33
717115e1	34	DEFINE_RATELIMIT_STATE(net_ratelimit_state, 5 * HZ, 10);
4ec93edb	35	/*
1da177e4	36	* All net warning printk()s should be guarded by this function.
4ec93edb	37	*/
1da177e4 LT	38	int net_ratelimit(void)
1da177e4 LT	39	{
717115e1	40	return __ratelimit(&net_ratelimit_state);
1da177e4	41	}
1da177e4	42	EXPORT_SYMBOL(net_ratelimit);
5e43db77 MM	43
	44	/*
	45	* Convert an ASCII string to binary IP.
	46	* This is outside of net/ipv4/ because various code that uses IP addresses
	47	* is otherwise not dependent on the TCP/IP stack.
	48	*/
	49
a2167dc6	50	__be32 in_aton(const char *str)
5e43db77	51	{
e013fb7c	52	unsigned int l;
5e43db77 MM	53	unsigned int val;
	54	int i;
	55
	56	l = 0;
46ba5b23	57	for (i = 0; i < 4; i++) {
5e43db77	58	l <<= 8;
46ba5b23	59	if (*str != '\0') {
5e43db77	60	val = 0;
46ba5b23	61	while (str != '\0' && str != '.' && *str != '\n') {
5e43db77 MM	62	val *= 10;
	63	val += *str - '0';
	64	str++;
	65	}
	66	l \|= val;
	67	if (*str != '\0')
	68	str++;
	69	}
	70	}
a02cec21	71	return htonl(l);
5e43db77	72	}
5e43db77	73	EXPORT_SYMBOL(in_aton);
1aaec67f YH	74
	75	#define IN6PTON_XDIGIT 0x00010000
	76	#define IN6PTON_DIGIT 0x00020000
	77	#define IN6PTON_COLON_MASK 0x00700000
	78	#define IN6PTON_COLON_1 0x00100000 /* single : requested */
	79	#define IN6PTON_COLON_2 0x00200000 /* second : requested */
	80	#define IN6PTON_COLON_1_2 0x00400000 /* :: requested */
	81	#define IN6PTON_DOT 0x00800000 /* . */
	82	#define IN6PTON_DELIM 0x10000000
	83	#define IN6PTON_NULL 0x20000000 /* first/tail */
	84	#define IN6PTON_UNKNOWN 0x40000000
	85
9a7c9337	86	static inline int xdigit2bin(char c, int delim)
1aaec67f	87	{
82fd5b5d AS	88	int val;
82fd5b5d AS	89
1aaec67f YH	90	if (c == delim \|\| c == '\0')
	91	return IN6PTON_DELIM;
	92	if (c == ':')
	93	return IN6PTON_COLON_MASK;
	94	if (c == '.')
	95	return IN6PTON_DOT;
82fd5b5d AS	96
	97	val = hex_to_bin(c);
	98	if (val >= 0)
	99	return val \| IN6PTON_XDIGIT \| (val < 10 ? IN6PTON_DIGIT : 0);
	100
9a7c9337 PM	101	if (delim == -1)
9a7c9337 PM	102	return IN6PTON_DELIM;
1aaec67f YH	103	return IN6PTON_UNKNOWN;
	104	}
	105
93ac0ef0 AW	106	/**
	107	* in4_pton - convert an IPv4 address from literal to binary representation
	108	* @src: the start of the IPv4 address string
	109	* @srclen: the length of the string, -1 means strlen(src)
	110	* @dst: the binary (u8[4] array) representation of the IPv4 address
	111	* @delim: the delimiter of the IPv4 address in @src, -1 means no delimiter
	112	* @end: A pointer to the end of the parsed string will be placed here
	113	*
	114	* Return one on success, return zero when any error occurs
	115	* and @end will point to the end of the parsed string.
	116	*
	117	*/
1aaec67f YH	118	int in4_pton(const char *src, int srclen,
1aaec67f YH	119	u8 *dst,
9a7c9337	120	int delim, const char **end)
1aaec67f YH	121	{
	122	const char *s;
	123	u8 *d;
	124	u8 dbuf[4];
	125	int ret = 0;
	126	int i;
	127	int w = 0;
	128
	129	if (srclen < 0)
	130	srclen = strlen(src);
	131	s = src;
	132	d = dbuf;
	133	i = 0;
8a01ed70	134	while (1) {
1aaec67f YH	135	int c;
1aaec67f YH	136	c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
83f03fa5	137	if (!(c & (IN6PTON_DIGIT \| IN6PTON_DOT \| IN6PTON_DELIM \| IN6PTON_COLON_MASK))) {
1aaec67f YH	138	goto out;
1aaec67f YH	139	}
83f03fa5	140	if (c & (IN6PTON_DOT \| IN6PTON_DELIM \| IN6PTON_COLON_MASK)) {
1aaec67f YH	141	if (w == 0)
	142	goto out;
	143	*d++ = w & 0xff;
	144	w = 0;
	145	i++;
83f03fa5	146	if (c & (IN6PTON_DELIM \| IN6PTON_COLON_MASK)) {
1aaec67f YH	147	if (i != 4)
	148	goto out;
	149	break;
	150	}
	151	goto cont;
	152	}
	153	w = (w * 10) + c;
	154	if ((w & 0xffff) > 255) {
	155	goto out;
	156	}
	157	cont:
	158	if (i >= 4)
	159	goto out;
	160	s++;
	161	srclen--;
	162	}
	163	ret = 1;
	164	memcpy(dst, dbuf, sizeof(dbuf));
	165	out:
	166	if (end)
	167	*end = s;
	168	return ret;
	169	}
1aaec67f YH	170	EXPORT_SYMBOL(in4_pton);
1aaec67f YH	171
28194fcd AW	172	/**
	173	* in6_pton - convert an IPv6 address from literal to binary representation
	174	* @src: the start of the IPv6 address string
	175	* @srclen: the length of the string, -1 means strlen(src)
	176	* @dst: the binary (u8[16] array) representation of the IPv6 address
	177	* @delim: the delimiter of the IPv6 address in @src, -1 means no delimiter
	178	* @end: A pointer to the end of the parsed string will be placed here
	179	*
	180	* Return one on success, return zero when any error occurs
	181	* and @end will point to the end of the parsed string.
	182	*
	183	*/
1aaec67f YH	184	int in6_pton(const char *src, int srclen,
1aaec67f YH	185	u8 *dst,
9a7c9337	186	int delim, const char **end)
1aaec67f YH	187	{
	188	const char s, tok = NULL;
	189	u8 d, dc = NULL;
	190	u8 dbuf[16];
	191	int ret = 0;
	192	int i;
	193	int state = IN6PTON_COLON_1_2 \| IN6PTON_XDIGIT \| IN6PTON_NULL;
	194	int w = 0;
	195
	196	memset(dbuf, 0, sizeof(dbuf));
	197
	198	s = src;
	199	d = dbuf;
	200	if (srclen < 0)
	201	srclen = strlen(src);
	202
1aaec67f YH	203	while (1) {
	204	int c;
	205
	206	c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
	207	if (!(c & state))
	208	goto out;
	209	if (c & (IN6PTON_DELIM \| IN6PTON_COLON_MASK)) {
	210	/* process one 16-bit word */
	211	if (!(state & IN6PTON_NULL)) {
	212	*d++ = (w >> 8) & 0xff;
	213	*d++ = w & 0xff;
	214	}
	215	w = 0;
	216	if (c & IN6PTON_DELIM) {
	217	/* We've processed last word */
	218	break;
	219	}
	220	/*
	221	* COLON_1 => XDIGIT
	222	* COLON_2 => XDIGIT\|DELIM
	223	* COLON_1_2 => COLON_2
	224	*/
	225	switch (state & IN6PTON_COLON_MASK) {
	226	case IN6PTON_COLON_2:
	227	dc = d;
	228	state = IN6PTON_XDIGIT \| IN6PTON_DELIM;
	229	if (dc - dbuf >= sizeof(dbuf))
	230	state \|= IN6PTON_NULL;
	231	break;
	232	case IN6PTON_COLON_1\|IN6PTON_COLON_1_2:
	233	state = IN6PTON_XDIGIT \| IN6PTON_COLON_2;
	234	break;
	235	case IN6PTON_COLON_1:
	236	state = IN6PTON_XDIGIT;
	237	break;
	238	case IN6PTON_COLON_1_2:
	239	state = IN6PTON_COLON_2;
	240	break;
	241	default:
	242	state = 0;
	243	}
	244	tok = s + 1;
	245	goto cont;
	246	}
	247
	248	if (c & IN6PTON_DOT) {
	249	ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s);
	250	if (ret > 0) {
	251	d += 4;
	252	break;
	253	}
	254	goto out;
	255	}
	256
	257	w = (w << 4) \| (0xff & c);
	258	state = IN6PTON_COLON_1 \| IN6PTON_DELIM;
	259	if (!(w & 0xf000)) {
	260	state \|= IN6PTON_XDIGIT;
	261	}
	262	if (!dc && d + 2 < dbuf + sizeof(dbuf)) {
	263	state \|= IN6PTON_COLON_1_2;
	264	state &= ~IN6PTON_DELIM;
	265	}
	266	if (d + 2 >= dbuf + sizeof(dbuf)) {
267	state &= ~(IN6PTON_COLON_1\|IN6PTON_COLON_1_2);
268	}
269	cont:
270	if ((dc && d + 4 < dbuf + sizeof(dbuf)) \|\|
271	d + 4 == dbuf + sizeof(dbuf)) {
272	state \|= IN6PTON_DOT;
273	}
274	if (d >= dbuf + sizeof(dbuf)) {
275	state &= ~(IN6PTON_XDIGIT\|IN6PTON_COLON_MASK);
276	}
277	s++;
278	srclen--;
279	}
280
281	i = 15; d--;
282
283	if (dc) {
8a01ed70	284	while (d >= dc)
1aaec67f	285	dst[i--] = *d--;
8a01ed70	286	while (i >= dc - dbuf)
1aaec67f	287	dst[i--] = 0;
8a01ed70	288	while (i >= 0)
1aaec67f YH	289	dst[i--] = *d--;
	290	} else
	291	memcpy(dst, dbuf, sizeof(dbuf));
	292
	293	ret = 1;
	294	out:
	295	if (end)
	296	*end = s;
	297	return ret;
	298	}
1aaec67f	299	EXPORT_SYMBOL(in6_pton);
a99a00cf	300
b1a951fe SG	301	static int inet4_pton(const char *src, u16 port_num,
	302	struct sockaddr_storage *addr)
	303	{
	304	struct sockaddr_in addr4 = (struct sockaddr_in )addr;
	305	int srclen = strlen(src);
	306
	307	if (srclen > INET_ADDRSTRLEN)
	308	return -EINVAL;
	309
	310	if (in4_pton(src, srclen, (u8 *)&addr4->sin_addr.s_addr,
	311	'\n', NULL) == 0)
	312	return -EINVAL;
	313
	314	addr4->sin_family = AF_INET;
	315	addr4->sin_port = htons(port_num);
	316
	317	return 0;
	318	}
	319
	320	static int inet6_pton(struct net net, const char src, u16 port_num,
	321	struct sockaddr_storage *addr)
	322	{
	323	struct sockaddr_in6 addr6 = (struct sockaddr_in6 )addr;
	324	const char *scope_delim;
	325	int srclen = strlen(src);
	326
	327	if (srclen > INET6_ADDRSTRLEN)
	328	return -EINVAL;
	329
	330	if (in6_pton(src, srclen, (u8 *)&addr6->sin6_addr.s6_addr,
	331	'%', &scope_delim) == 0)
	332	return -EINVAL;
	333
	334	if (ipv6_addr_type(&addr6->sin6_addr) & IPV6_ADDR_LINKLOCAL &&
	335	src + srclen != scope_delim && *scope_delim == '%') {
	336	struct net_device *dev;
	337	char scope_id[16];
a88086e0	338	size_t scope_len = min_t(size_t, sizeof(scope_id) - 1,
b1a951fe SG	339	src + srclen - scope_delim - 1);
	340
	341	memcpy(scope_id, scope_delim + 1, scope_len);
	342	scope_id[scope_len] = '\0';
	343
	344	dev = dev_get_by_name(net, scope_id);
	345	if (dev) {
	346	addr6->sin6_scope_id = dev->ifindex;
	347	dev_put(dev);
	348	} else if (kstrtouint(scope_id, 0, &addr6->sin6_scope_id)) {
	349	return -EINVAL;
	350	}
	351	}
	352
	353	addr6->sin6_family = AF_INET6;
	354	addr6->sin6_port = htons(port_num);
	355
	356	return 0;
	357	}
	358
	359	/**
	360	* inet_pton_with_scope - convert an IPv4/IPv6 and port to socket address
	361	* @net: net namespace (used for scope handling)
	362	* @af: address family, AF_INET, AF_INET6 or AF_UNSPEC for either
	363	* @src: the start of the address string
	364	* @port: the start of the port string (or NULL for none)
	365	* @addr: output socket address
	366	*
	367	* Return zero on success, return errno when any error occurs.
	368	*/
	369	int inet_pton_with_scope(struct net *net, __kernel_sa_family_t af,
	370	const char src, const char port, struct sockaddr_storage *addr)
	371	{
	372	u16 port_num;
	373	int ret = -EINVAL;
	374
	375	if (port) {
	376	if (kstrtou16(port, 0, &port_num))
	377	return -EINVAL;
	378	} else {
	379	port_num = 0;
	380	}
	381
	382	switch (af) {
	383	case AF_INET:
	384	ret = inet4_pton(src, port_num, addr);
	385	break;
	386	case AF_INET6:
	387	ret = inet6_pton(net, src, port_num, addr);
	388	break;
	389	case AF_UNSPEC:
	390	ret = inet4_pton(src, port_num, addr);
	391	if (ret)
	392	ret = inet6_pton(net, src, port_num, addr);
	393	break;
	394	default:
	395	pr_err("unexpected address family %d\n", af);
07d53ae4	396	}
b1a951fe SG	397
	398	return ret;
	399	}
	400	EXPORT_SYMBOL(inet_pton_with_scope);
	401
a470143f SG	402	bool inet_addr_is_any(struct sockaddr *addr)
	403	{
	404	if (addr->sa_family == AF_INET6) {
	405	struct sockaddr_in6 in6 = (struct sockaddr_in6 )addr;
	406	const struct sockaddr_in6 in6_any =
	407	{ .sin6_addr = IN6ADDR_ANY_INIT };
	408
	409	if (!memcmp(in6->sin6_addr.s6_addr,
	410	in6_any.sin6_addr.s6_addr, 16))
	411	return true;
	412	} else if (addr->sa_family == AF_INET) {
	413	struct sockaddr_in in = (struct sockaddr_in )addr;
	414
	415	if (in->sin_addr.s_addr == htonl(INADDR_ANY))
	416	return true;
	417	} else {
	418	pr_warn("unexpected address family %u\n", addr->sa_family);
	419	}
	420
	421	return false;
	422	}
	423	EXPORT_SYMBOL(inet_addr_is_any);
	424
a99a00cf	425	void inet_proto_csum_replace4(__sum16 sum, struct sk_buff skb,
4b048d6d	426	__be32 from, __be32 to, bool pseudohdr)
a99a00cf	427	{
a99a00cf	428	if (skb->ip_summed != CHECKSUM_PARTIAL) {
05c98543	429	csum_replace4(sum, from, to);
a99a00cf	430	if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
05c98543 ED	431	skb->csum = ~csum_add(csum_sub(~(skb->csum),
	432	(__force __wsum)from),
	433	(__force __wsum)to);
a99a00cf	434	} else if (pseudohdr)
05c98543 ED	435	sum = ~csum_fold(csum_add(csum_sub(csum_unfold(sum),
	436	(__force __wsum)from),
	437	(__force __wsum)to));
a99a00cf PM	438	}
a99a00cf PM	439	EXPORT_SYMBOL(inet_proto_csum_replace4);
4940fc88	440
189c9b1e PC	441	/**
	442	* inet_proto_csum_replace16 - update layer 4 header checksum field
	443	* @sum: Layer 4 header checksum field
	444	* @skb: sk_buff for the packet
	445	* @from: old IPv6 address
	446	* @to: new IPv6 address
	447	* @pseudohdr: True if layer 4 header checksum includes pseudoheader
	448	*
	449	* Update layer 4 header as per the update in IPv6 src/dst address.
	450	*
	451	* There is no need to update skb->csum in this function, because update in two
	452	* fields a.) IPv6 src/dst address and b.) L4 header checksum cancels each other
	453	* for skb->csum calculation. Whereas inet_proto_csum_replace4 function needs to
	454	* update skb->csum, because update in 3 fields a.) IPv4 src/dst address,
	455	* b.) IPv4 Header checksum and c.) L4 header checksum results in same diff as
	456	* L4 Header checksum for skb->csum calculation.
	457	*/
2cf545e8 PM	458	void inet_proto_csum_replace16(__sum16 sum, struct sk_buff skb,
2cf545e8 PM	459	const __be32 from, const __be32 to,
4b048d6d	460	bool pseudohdr)
2cf545e8 PM	461	{
	462	__be32 diff[] = {
	463	~from[0], ~from[1], ~from[2], ~from[3],
	464	to[0], to[1], to[2], to[3],
	465	};
	466	if (skb->ip_summed != CHECKSUM_PARTIAL) {
	467	*sum = csum_fold(csum_partial(diff, sizeof(diff),
	468	~csum_unfold(*sum)));
2cf545e8 PM	469	} else if (pseudohdr)
	470	*sum = ~csum_fold(csum_partial(diff, sizeof(diff),
	471	csum_unfold(*sum)));
	472	}
	473	EXPORT_SYMBOL(inet_proto_csum_replace16);
a48e4292	474
abc5d1ff TH	475	void inet_proto_csum_replace_by_diff(__sum16 sum, struct sk_buff skb,
	476	__wsum diff, bool pseudohdr)
	477	{
	478	if (skb->ip_summed != CHECKSUM_PARTIAL) {
	479	sum = csum_fold(csum_add(diff, ~csum_unfold(sum)));
	480	if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
	481	skb->csum = ~csum_add(diff, ~skb->csum);
	482	} else if (pseudohdr) {
	483	sum = ~csum_fold(csum_add(diff, csum_unfold(sum)));
	484	}
	485	}
	486	EXPORT_SYMBOL(inet_proto_csum_replace_by_diff);