57 lines
1.3 KiB
C
57 lines
1.3 KiB
C
/**
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* @file kernel/vfs/random.c
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* @brief Bad RNG.
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*
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* Provides a terrible little xorshift random number generator.
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*
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* @copyright
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* This file is part of ToaruOS and is released under the terms
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* of the NCSA / University of Illinois License - see LICENSE.md
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* Copyright (C) 2014-2018 K. Lange
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*/
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#include <stdint.h>
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#include <kernel/vfs.h>
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#include <kernel/string.h>
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static uint32_t rand(void) {
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static uint32_t x = 123456789;
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static uint32_t y = 362436069;
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static uint32_t z = 521288629;
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static uint32_t w = 88675123;
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uint32_t t;
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t = x ^ (x << 11);
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x = y; y = z; z = w;
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return w = w ^ (w >> 19) ^ t ^ (t >> 8);
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}
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static uint64_t read_random(fs_node_t *node, uint64_t offset, uint64_t size, uint8_t *buffer) {
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size_t s = 0;
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while (s < size) {
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buffer[s] = rand() % 0xFF;
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s++;
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}
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return size;
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}
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static fs_node_t * random_device_create(void) {
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fs_node_t * fnode = malloc(sizeof(fs_node_t));
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memset(fnode, 0x00, sizeof(fs_node_t));
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fnode->inode = 0;
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strcpy(fnode->name, "random");
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fnode->uid = 0;
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fnode->gid = 0;
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fnode->mask = 0444;
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fnode->length = 1024;
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fnode->flags = FS_CHARDEVICE;
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fnode->read = read_random;
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return fnode;
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}
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void random_initialize(void) {
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vfs_mount("/dev/random", random_device_create());
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vfs_mount("/dev/urandom", random_device_create());
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}
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