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- /*
- * Generic address resultion entity
- *
- * Authors:
- * net_random Alan Cox
- * net_ratelimit Andy 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);
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