/*
* 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/random.h>
#include <linux/percpu.h>
#include <linux/init.h>
#include <asm/byteorder.h>
#include <asm/system.h>
#include <asm/uaccess.h>
/*
This is a maximally equidistributed combined Tausworthe generator
based on code from GNU Scientific Library 1.5 (30 Jun 2004)
x_n = (s1_n ^ s2_n ^ s3_n)
s1_{n+1} = (((s1_n & 4294967294) <<12) ^ (((s1_n <<13) ^ s1_n) >>19))
s2_{n+1} = (((s2_n & 4294967288) << 4) ^ (((s2_n << 2) ^ s2_n) >>25))
s3_{n+1} = (((s3_n & 4294967280) <<17) ^ (((s3_n << 3) ^ s3_n) >>11))
The period of this generator is about 2^88.
From: P. L'Ecuyer, "Maximally Equidistributed Combined Tausworthe
Generators", Mathematics of Computation, 65, 213 (1996), 203--213.
This is available on the net from L'Ecuyer's home page,
http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
ftp://ftp.iro.umontreal.ca/pub/simulation/lecuyer/papers/tausme.ps
There is an erratum in the paper "Tables of Maximally
Equidistributed Combined LFSR Generators", Mathematics of
Computation, 68, 225 (1999), 261--269:
http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
... the k_j most significant bits of z_j must be non-
zero, for each j. (Note: this restriction also applies to the
computer code given in [4], but was mistakenly not mentioned in
that paper.)
This affects the seeding procedure by imposing the requirement
s1 > 1, s2 > 7, s3 > 15.
*/
struct nrnd_state {
u32 s1, s2, s3;
};
static DEFINE_PER_CPU(struct nrnd_state, net_rand_state);
static u32 __net_random(struct nrnd_state *state)
{
#define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b)
state->s1 = TAUSWORTHE(state->s1, 13, 19, 4294967294UL, 12);
state->s2 = TAUSWORTHE(state->s2, 2, 25, 4294967288UL, 4);
state->s3 = TAUSWORTHE(state->s3, 3, 11, 4294967280UL, 17);
return (state->s1 ^ state->s2 ^ state->s3);
}
static void __net_srandom(struct nrnd_state *state, unsigned long s)
{
if (s == 0)
s = 1; /* default seed is 1 */
#define LCG(n) (69069 * n)
state->s1 = LCG(s);
state->s2 = LCG(state->s1);
state->s3 = LCG(state->s2);
/* "warm it up" */
__net_random(state);
__net_random(state);
__net_random(state);
__net_random(state);
__net_random(state);
__net_random(state);
}
unsigned long net_random(void)
{
unsigned long r;
struct nrnd_state *state = &get_cpu_var(net_rand_state);
r = __net_random(state);
put_cpu_var(state);
return r;
}
void net_srandom(unsigned long entropy)
{
struct nrnd_state *state = &get_cpu_var(net_rand_state);
__net_srandom(state, state->s1^entropy);
put_cpu_var(state);
}
void __init net_random_init(void)
{
int i;
for_each_possible_cpu(i) {
struct nrnd_state *state = &per_cpu(net_rand_state,i);
__net_srandom(state, i+jiffies);
}
}
static int net_random_reseed(void)
{
int i;
unsigned long seed;
for_each_possible_cpu(i) {
struct nrnd_state *state = &per_cpu(net_rand_state,i);
get_random_bytes(&seed, sizeof(seed));
__net_srandom(state, seed);
}
return 0;
}
late_initcall(net_random_reseed);
int net_msg_cost = 5*HZ;
int net_msg_burst = 10;
/*
* All net warning printk()s should be guarded by this function.
*/
int net_ratelimit(void)
{
return __printk_ratelimit(net_msg_cost, net_msg_burst);
}
EXPORT_SYMBOL(net_random);
EXPORT_SYMBOL(net_ratelimit);
EXPORT_SYMBOL(net_srandom);
/*
* 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 digit2bin(char c, char delim)
{
if (c == delim || c == '\0')
return IN6PTON_DELIM;
if (c == '.')
return IN6PTON_DOT;
if (c >= '0' && c <= '9')
return (IN6PTON_DIGIT | (c - '0'));
return IN6PTON_UNKNOWN;
}
static inline int xdigit2bin(char c, char delim)
{
if (c == delim || c == '\0')
return IN6PTON_DELIM;
if (c == ':')
return IN6PTON_COLON_MASK;
if (c == '.')
return IN6PTON_DOT;
if (c >= '0' && c <= '9')
return (IN6PTON_XDIGIT | IN6PTON_DIGIT| (c - '0'));
if (c >= 'a' && c <= 'f')
return (IN6PTON_XDIGIT | (c - 'a' + 10));
if (c >= 'A' && c <= 'F')
return (IN6PTON_XDIGIT | (c - 'A' + 10));
return IN6PTON_UNKNOWN;
}
int in4_pton(const char *src, int srclen,
u8 *dst,
char 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))) {
goto out;
}
if (c & (IN6PTON_DOT | IN6PTON_DELIM)) {
if (w == 0)
goto out;
*d++ = w & 0xff;
w = 0;
i++;
if (c & IN6PTON_DELIM) {
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,
char 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);
