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/* *	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 <kuznet@ms2.inr.ac.ru> * *	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/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 <net/sock.h>#include <net/net_ratelimit.h> #include <asm/byteorder.h>#include <asm/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 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;} /** * 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); 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); 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)));		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_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); struct __net_random_once_work {	struct work_struct work;	struct static_key *key;}; static void __net_random_once_deferred(struct work_struct *w){	struct __net_random_once_work *work =		container_of(w, struct __net_random_once_work, work);	BUG_ON(!static_key_enabled(work->key));	static_key_slow_dec(work->key);	kfree(work);} static void __net_random_once_disable_jump(struct static_key *key){	struct __net_random_once_work *w; 	w = kmalloc(sizeof(*w), GFP_ATOMIC);	if (!w)		return; 	INIT_WORK(&w->work, __net_random_once_deferred);	w->key = key;	schedule_work(&w->work);} bool __net_get_random_once(void *buf, int nbytes, bool *done,			   struct static_key *once_key){	static DEFINE_SPINLOCK(lock);	unsigned long flags; 	spin_lock_irqsave(&lock, flags);	if (*done) {		spin_unlock_irqrestore(&lock, flags);		return false;	} 	get_random_bytes(buf, nbytes);	*done = true;	spin_unlock_irqrestore(&lock, flags); 	__net_random_once_disable_jump(once_key); 	return true;}EXPORT_SYMBOL(__net_get_random_once);