- 根目录:
- 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 <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/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);