| /* |
| * 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); |
| |
| printf("srclen=%d\n", srclen); |
| |
| 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); |