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// SPDX-License-Identifier: GPL-2.0-or-later/* *	Generic address resolution 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 <kuznet@ms2.inr.ac.ru> */ #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;	size_t 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;	size_t 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) {		csum_replace_by_diff(sum, diff);		if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)			skb->csum = ~csum_sub(diff, skb->csum);	} else if (pseudohdr) {		*sum = ~csum_fold(csum_add(diff, csum_unfold(*sum)));	}}EXPORT_SYMBOL(inet_proto_csum_replace_by_diff);