From eb8dd9dca1228af0cd132f515509051ecfabf6f6 Mon Sep 17 00:00:00 2001 From: cvs2svn Date: Mon, 14 Apr 2025 17:32:06 +0000 Subject: This commit was manufactured by cvs2git to create tag 'tb_20250414'. --- src/lib/libc/stdlib/random.c | 419 ------------------------------------------- 1 file changed, 419 deletions(-) delete mode 100644 src/lib/libc/stdlib/random.c (limited to 'src/lib/libc/stdlib/random.c') diff --git a/src/lib/libc/stdlib/random.c b/src/lib/libc/stdlib/random.c deleted file mode 100644 index 62a0c24bdb..0000000000 --- a/src/lib/libc/stdlib/random.c +++ /dev/null @@ -1,419 +0,0 @@ -/* $OpenBSD: random.c,v 1.31 2017/11/28 06:55:49 tb Exp $ */ -/* - * Copyright (c) 1983 Regents of the University of California. - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -#include -#include -#include -#include - -#include "thread_private.h" - -/* - * random.c: - * - * An improved random number generation package. In addition to the standard - * rand()/srand() like interface, this package also has a special state info - * interface. The initstate() routine is called with a seed, an array of - * bytes, and a count of how many bytes are being passed in; this array is - * then initialized to contain information for random number generation with - * that much state information. Good sizes for the amount of state - * information are 32, 64, 128, and 256 bytes. The state can be switched by - * calling the setstate() routine with the same array as was initiallized - * with initstate(). By default, the package runs with 128 bytes of state - * information and generates far better random numbers than a linear - * congruential generator. If the amount of state information is less than - * 32 bytes, a simple linear congruential R.N.G. is used. - * - * Internally, the state information is treated as an array of int32_t; the - * zeroeth element of the array is the type of R.N.G. being used (small - * integer); the remainder of the array is the state information for the - * R.N.G. Thus, 32 bytes of state information will give 7 int32_ts worth of - * state information, which will allow a degree seven polynomial. (Note: - * the zeroeth word of state information also has some other information - * stored in it -- see setstate() for details). - * - * The random number generation technique is a linear feedback shift register - * approach, employing trinomials (since there are fewer terms to sum up that - * way). In this approach, the least significant bit of all the numbers in - * the state table will act as a linear feedback shift register, and will - * have period 2^deg - 1 (where deg is the degree of the polynomial being - * used, assuming that the polynomial is irreducible and primitive). The - * higher order bits will have longer periods, since their values are also - * influenced by pseudo-random carries out of the lower bits. The total - * period of the generator is approximately deg*(2**deg - 1); thus doubling - * the amount of state information has a vast influence on the period of the - * generator. Note: the deg*(2**deg - 1) is an approximation only good for - * large deg, when the period of the shift register is the dominant factor. - * With deg equal to seven, the period is actually much longer than the - * 7*(2**7 - 1) predicted by this formula. - */ - -/* - * For each of the currently supported random number generators, we have a - * break value on the amount of state information (you need at least this - * many bytes of state info to support this random number generator), a degree - * for the polynomial (actually a trinomial) that the R.N.G. is based on, and - * the separation between the two lower order coefficients of the trinomial. - */ -#define TYPE_0 0 /* linear congruential */ -#define BREAK_0 8 -#define DEG_0 0 -#define SEP_0 0 - -#define TYPE_1 1 /* x**7 + x**3 + 1 */ -#define BREAK_1 32 -#define DEG_1 7 -#define SEP_1 3 - -#define TYPE_2 2 /* x**15 + x + 1 */ -#define BREAK_2 64 -#define DEG_2 15 -#define SEP_2 1 - -#define TYPE_3 3 /* x**31 + x**3 + 1 */ -#define BREAK_3 128 -#define DEG_3 31 -#define SEP_3 3 - -#define TYPE_4 4 /* x**63 + x + 1 */ -#define BREAK_4 256 -#define DEG_4 63 -#define SEP_4 1 - -/* - * Array versions of the above information to make code run faster -- - * relies on fact that TYPE_i == i. - */ -#define MAX_TYPES 5 /* max number of types above */ - -static int degrees[MAX_TYPES] = { DEG_0, DEG_1, DEG_2, DEG_3, DEG_4 }; -static int seps [MAX_TYPES] = { SEP_0, SEP_1, SEP_2, SEP_3, SEP_4 }; - -/* - * Initially, everything is set up as if from: - * - * initstate(1, &randtbl, 128); - * - * Note that this initialization takes advantage of the fact that srandom() - * advances the front and rear pointers 10*rand_deg times, and hence the - * rear pointer which starts at 0 will also end up at zero; thus the zeroeth - * element of the state information, which contains info about the current - * position of the rear pointer is just - * - * MAX_TYPES * (rptr - state) + TYPE_3 == TYPE_3. - */ - -static int32_t randtbl[DEG_3 + 1] = { - TYPE_3, - 0x991539b1, 0x16a5bce3, 0x6774a4cd, 0x3e01511e, 0x4e508aaa, 0x61048c05, - 0xf5500617, 0x846b7115, 0x6a19892c, 0x896a97af, 0xdb48f936, 0x14898454, - 0x37ffd106, 0xb58bff9c, 0x59e17104, 0xcf918a49, 0x09378c83, 0x52c7a471, - 0x8d293ea9, 0x1f4fc301, 0xc3db71be, 0x39b44e1c, 0xf8a44ef9, 0x4c8b80b1, - 0x19edc328, 0x87bf4bdd, 0xc9b240e5, 0xe9ee4b1b, 0x4382aee7, 0x535b6b41, - 0xf3bec5da, -}; - -/* - * fptr and rptr are two pointers into the state info, a front and a rear - * pointer. These two pointers are always rand_sep places aparts, as they - * cycle cyclically through the state information. (Yes, this does mean we - * could get away with just one pointer, but the code for random() is more - * efficient this way). The pointers are left positioned as they would be - * from the call - * - * initstate(1, randtbl, 128); - * - * (The position of the rear pointer, rptr, is really 0 (as explained above - * in the initialization of randtbl) because the state table pointer is set - * to point to randtbl[1] (as explained below). - */ -static int32_t *fptr = &randtbl[SEP_3 + 1]; -static int32_t *rptr = &randtbl[1]; - -/* - * The following things are the pointer to the state information table, the - * type of the current generator, the degree of the current polynomial being - * used, and the separation between the two pointers. Note that for efficiency - * of random(), we remember the first location of the state information, not - * the zeroeth. Hence it is valid to access state[-1], which is used to - * store the type of the R.N.G. Also, we remember the last location, since - * this is more efficient than indexing every time to find the address of - * the last element to see if the front and rear pointers have wrapped. - */ -static int32_t *state = &randtbl[1]; -static int32_t *end_ptr = &randtbl[DEG_3 + 1]; -static int rand_type = TYPE_3; -static int rand_deg = DEG_3; -static int rand_sep = SEP_3; - -static int random_deterministic; - -static void *random_mutex; -static long random_l(void); - -#define LOCK() _MUTEX_LOCK(&random_mutex) -#define UNLOCK() _MUTEX_UNLOCK(&random_mutex) - -/* - * srandom: - * - * Initialize the random number generator based on the given seed. If the - * type is the trivial no-state-information type, just remember the seed. - * Otherwise, initializes state[] based on the given "seed" via a linear - * congruential generator. Then, the pointers are set to known locations - * that are exactly rand_sep places apart. Lastly, it cycles the state - * information a given number of times to get rid of any initial dependencies - * introduced by the L.C.R.N.G. Note that the initialization of randtbl[] - * for default usage relies on values produced by this routine. - */ -static void -srandom_l(unsigned int x) -{ - int i; - int32_t test; - div_t val; - - random_deterministic = 1; - if (rand_type == TYPE_0) - state[0] = x; - else { - /* A seed of 0 would result in state[] always being zero. */ - state[0] = x ? x : 1; - for (i = 1; i < rand_deg; i++) { - /* - * Implement the following, without overflowing 31 bits: - * - * state[i] = (16807 * state[i - 1]) % 2147483647; - * - * 2^31-1 (prime) = 2147483647 = 127773*16807+2836 - */ - val = div(state[i-1], 127773); - test = 16807 * val.rem - 2836 * val.quot; - state[i] = test + (test < 0 ? 2147483647 : 0); - } - fptr = &state[rand_sep]; - rptr = &state[0]; - for (i = 0; i < 10 * rand_deg; i++) - (void)random_l(); - } -} - -void -srandom(unsigned int x) -{ - random_deterministic = 0; -} - -void -srandomdev(void) -{ - random_deterministic = 0; /* back to the default */ -} - -void -srandom_deterministic(unsigned int x) -{ - LOCK(); - srandom_l(x); - UNLOCK(); -} - -/* - * initstate: - * - * Initialize the state information in the given array of n bytes for future - * random number generation. Based on the number of bytes we are given, and - * the break values for the different R.N.G.'s, we choose the best (largest) - * one we can and set things up for it. srandom() is then called to - * initialize the state information. - * - * Note that on return from srandom(), we set state[-1] to be the type - * multiplexed with the current value of the rear pointer; this is so - * successive calls to initstate() won't lose this information and will be - * able to restart with setstate(). - * - * Note: the first thing we do is save the current state, if any, just like - * setstate() so that it doesn't matter when initstate is called. - * - * Returns a pointer to the old state. - */ -char * -initstate(u_int seed, char *arg_state, size_t n) -{ - char *ostate = (char *)(&state[-1]); - - LOCK(); - random_deterministic = 1; - if (rand_type == TYPE_0) - state[-1] = rand_type; - else - state[-1] = MAX_TYPES * (rptr - state) + rand_type; - if (n < BREAK_0) { - UNLOCK(); - return(NULL); - } - if (n < BREAK_1) { - rand_type = TYPE_0; - rand_deg = DEG_0; - rand_sep = SEP_0; - } else if (n < BREAK_2) { - rand_type = TYPE_1; - rand_deg = DEG_1; - rand_sep = SEP_1; - } else if (n < BREAK_3) { - rand_type = TYPE_2; - rand_deg = DEG_2; - rand_sep = SEP_2; - } else if (n < BREAK_4) { - rand_type = TYPE_3; - rand_deg = DEG_3; - rand_sep = SEP_3; - } else { - rand_type = TYPE_4; - rand_deg = DEG_4; - rand_sep = SEP_4; - } - state = &(((int32_t *)arg_state)[1]); /* first location */ - end_ptr = &state[rand_deg]; /* must set end_ptr before srandom */ - srandom_l(seed); - if (rand_type == TYPE_0) - state[-1] = rand_type; - else - state[-1] = MAX_TYPES*(rptr - state) + rand_type; - UNLOCK(); - return(ostate); -} - -/* - * setstate: - * - * Restore the state from the given state array. - * - * Note: it is important that we also remember the locations of the pointers - * in the current state information, and restore the locations of the pointers - * from the old state information. This is done by multiplexing the pointer - * location into the zeroeth word of the state information. - * - * Note that due to the order in which things are done, it is OK to call - * setstate() with the same state as the current state. - * - * Returns a pointer to the old state information. - */ -char * -setstate(char *arg_state) -{ - int32_t *new_state = (int32_t *)arg_state; - int32_t type = new_state[0] % MAX_TYPES; - int32_t rear = new_state[0] / MAX_TYPES; - char *ostate = (char *)(&state[-1]); - - LOCK(); - random_deterministic = 1; - if (rand_type == TYPE_0) - state[-1] = rand_type; - else - state[-1] = MAX_TYPES * (rptr - state) + rand_type; - switch(type) { - case TYPE_0: - case TYPE_1: - case TYPE_2: - case TYPE_3: - case TYPE_4: - rand_type = type; - rand_deg = degrees[type]; - rand_sep = seps[type]; - break; - default: - UNLOCK(); - return(NULL); - } - state = &new_state[1]; - if (rand_type != TYPE_0) { - rptr = &state[rear]; - fptr = &state[(rear + rand_sep) % rand_deg]; - } - end_ptr = &state[rand_deg]; /* set end_ptr too */ - UNLOCK(); - return(ostate); -} - -/* - * random: - * - * If we are using the trivial TYPE_0 R.N.G., just do the old linear - * congruential bit. Otherwise, we do our fancy trinomial stuff, which is - * the same in all the other cases due to all the global variables that have - * been set up. The basic operation is to add the number at the rear pointer - * into the one at the front pointer. Then both pointers are advanced to - * the next location cyclically in the table. The value returned is the sum - * generated, reduced to 31 bits by throwing away the "least random" low bit. - * - * Note: the code takes advantage of the fact that both the front and - * rear pointers can't wrap on the same call by not testing the rear - * pointer if the front one has wrapped. - * - * Returns a 31-bit random number. - */ -static long -random_l(void) -{ - int32_t i; - - if (random_deterministic == 0) - return arc4random() & 0x7fffffff; - - if (rand_type == TYPE_0) - i = state[0] = (state[0] * 1103515245 + 12345) & 0x7fffffff; - else { - *fptr += *rptr; - i = (*fptr >> 1) & 0x7fffffff; /* chucking least random bit */ - if (++fptr >= end_ptr) { - fptr = state; - ++rptr; - } else if (++rptr >= end_ptr) - rptr = state; - } - return((long)i); -} - -long -random(void) -{ - long r; - LOCK(); - r = random_l(); - UNLOCK(); - return r; -} - -#if defined(APIWARN) -__warn_references(random, - "random() may return deterministic values, is that what you want?"); -#endif -- cgit v1.2.3-55-g6feb