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@ r28530:9741a9739150
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Location: cpp/openttd-patchpack/source/src/core/random_func.cpp
r28530:9741a9739150
4.5 KiB
text/x-c
Fix bd85f61a: [Linux] don't include sys/random.h on older glibc systems (#11844)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 | /*
* This file is part of OpenTTD.
* OpenTTD 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, version 2.
* OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file random_func.cpp Implementation of the pseudo random generator. */
#include "../stdafx.h"
#include "random_func.hpp"
#include "bitmath_func.hpp"
#include "../debug.h"
#ifdef RANDOM_DEBUG
#include "../network/network.h"
#include "../network/network_server.h"
#include "../network/network_internal.h"
#include "../company_func.h"
#include "../fileio_func.h"
#include "../timer/timer_game_calendar.h"
#endif /* RANDOM_DEBUG */
#if defined(_WIN32)
# include <windows.h>
# include <bcrypt.h>
#elif defined(__APPLE__) || defined(__NetBSD__) || defined(__FreeBSD__)
// No includes required.
#elif defined(__GLIBC__) && ((__GLIBC__ > 2) || ((__GLIBC__ == 2) && (__GLIBC_MINOR__ >= 25)))
# include <sys/random.h>
#elif defined(__EMSCRIPTEN__)
# include <emscripten.h>
#endif
#include "../safeguards.h"
Randomizer _random, _interactive_random;
/**
* Generate the next pseudo random number
* @return the random number
*/
uint32_t Randomizer::Next()
{
const uint32_t s = this->state[0];
const uint32_t t = this->state[1];
this->state[0] = s + std::rotr(t ^ 0x1234567F, 7) + 1;
return this->state[1] = std::rotr(s, 3) - 1;
}
/**
* Generate the next pseudo random number scaled to \a limit, excluding \a limit
* itself.
* @param limit Limit of the range to be generated from.
* @return Random number in [0,\a limit)
*/
uint32_t Randomizer::Next(uint32_t limit)
{
return ((uint64_t)this->Next() * (uint64_t)limit) >> 32;
}
/**
* (Re)set the state of the random number generator.
* @param seed the new state
*/
void Randomizer::SetSeed(uint32_t seed)
{
this->state[0] = seed;
this->state[1] = seed;
}
/**
* (Re)set the state of the random number generators.
* @param seed the new state
*/
void SetRandomSeed(uint32_t seed)
{
_random.SetSeed(seed);
_interactive_random.SetSeed(seed * 0x1234567);
}
#ifdef RANDOM_DEBUG
uint32_t DoRandom(int line, const char *file)
{
if (_networking && (!_network_server || (NetworkClientSocket::IsValidID(0) && NetworkClientSocket::Get(0)->status != NetworkClientSocket::STATUS_INACTIVE))) {
Debug(random, 0, "{:08x}; {:02x}; {:04x}; {:02x}; {}:{}", TimerGameCalendar::date, TimerGameCalendar::date_fract, _frame_counter, (byte)_current_company, file, line);
}
return _random.Next();
}
uint32_t DoRandomRange(uint32_t limit, int line, const char *file)
{
return ((uint64_t)DoRandom(line, file) * (uint64_t)limit) >> 32;
}
#endif /* RANDOM_DEBUG */
/**
* Fill the given buffer with random bytes.
*
* This function will attempt to use a cryptographically-strong random
* generator, but will fall back to a weaker random generator if none is
* available.
*
* In the end, the buffer will always be filled with some form of random
* bytes when this function returns.
*
* @param buf The buffer to fill with random bytes.
*/
void RandomBytesWithFallback(std::span<uint8_t> buf)
{
#if defined(_WIN32)
auto res = BCryptGenRandom(nullptr, static_cast<PUCHAR>(buf.data()), static_cast<ULONG>(buf.size()), BCRYPT_USE_SYSTEM_PREFERRED_RNG);
if (res >= 0) return;
#elif defined(__APPLE__) || defined(__NetBSD__) || defined(__FreeBSD__)
arc4random_buf(buf.data(), buf.size());
return;
#elif defined(__GLIBC__) && ((__GLIBC__ > 2) || ((__GLIBC__ == 2) && (__GLIBC_MINOR__ >= 25)))
auto res = getrandom(buf.data(), buf.size(), 0);
if (res > 0 && static_cast<size_t>(res) == buf.size()) return;
#elif defined(__EMSCRIPTEN__)
auto res = EM_ASM_INT({
var buf = $0;
var bytes = $1;
var crypto = window.crypto;
if (crypto === undefined || crypto.getRandomValues === undefined) {
return -1;
}
crypto.getRandomValues(Module.HEAPU8.subarray(buf, buf + bytes));
return 1;
}, buf.data(), buf.size());
if (res > 0) return;
#else
# warning "No cryptographically-strong random generator available; using a fallback instead"
#endif
static bool warned_once = false;
Debug(misc, warned_once ? 1 : 0, "Cryptographically-strong random generator unavailable; using fallback");
warned_once = true;
for (uint i = 0; i < buf.size(); i++) {
buf[i] = static_cast<uint8_t>(InteractiveRandom());
}
}
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