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/*
* OS and machine specific utility functions
* (C) 2015,2016,2017,2018 Jack Lloyd
* (C) 2016 Daniel Neus
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/internal/os_utils.h>
#include <botan/cpuid.h>
#include <botan/exceptn.h>
#include <botan/mem_ops.h>
#include <algorithm>
#include <chrono>
#include <cstdlib>
#if defined(BOTAN_TARGET_OS_HAS_THREADS)
#include <thread>
#endif
#if defined(BOTAN_TARGET_OS_HAS_EXPLICIT_BZERO)
#include <string.h>
#endif
#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
#include <sys/types.h>
#include <sys/resource.h>
#include <sys/mman.h>
#include <signal.h>
#include <stdlib.h>
#include <setjmp.h>
#include <unistd.h>
#include <errno.h>
#include <termios.h>
#undef B0
#endif
#if defined(BOTAN_TARGET_OS_IS_EMSCRIPTEN)
#include <emscripten/emscripten.h>
#endif
#if defined(BOTAN_TARGET_OS_HAS_GETAUXVAL) || defined(BOTAN_TARGET_OS_IS_ANDROID) || \
defined(BOTAN_TARGET_OS_HAS_ELF_AUX_INFO)
#include <sys/auxv.h>
#endif
#if defined(BOTAN_TARGET_OS_HAS_WIN32)
#define NOMINMAX 1
#define _WINSOCKAPI_ // stop windows.h including winsock.h
#include <windows.h>
#endif
#if defined(BOTAN_TARGET_OS_IS_ANDROID)
#include <elf.h>
extern "C" char **environ;
#endif
#if defined(BOTAN_TARGET_OS_IS_IOS) || defined(BOTAN_TARGET_OS_IS_MACOS)
#include <mach/vm_statistics.h>
#endif
namespace Botan {
// Not defined in OS namespace for historical reasons
void secure_scrub_memory(void* ptr, size_t n)
{
#if defined(BOTAN_TARGET_OS_HAS_RTLSECUREZEROMEMORY)
::RtlSecureZeroMemory(ptr, n);
#elif defined(BOTAN_TARGET_OS_HAS_EXPLICIT_BZERO)
::explicit_bzero(ptr, n);
#elif defined(BOTAN_TARGET_OS_HAS_EXPLICIT_MEMSET)
(void)::explicit_memset(ptr, 0, n);
#elif defined(BOTAN_USE_VOLATILE_MEMSET_FOR_ZERO) && (BOTAN_USE_VOLATILE_MEMSET_FOR_ZERO == 1)
/*
Call memset through a static volatile pointer, which the compiler
should not elide. This construct should be safe in conforming
compilers, but who knows. I did confirm that on x86-64 GCC 6.1 and
Clang 3.8 both create code that saves the memset address in the
data segment and unconditionally loads and jumps to that address.
*/
static void* (*const volatile memset_ptr)(void*, int, size_t) = std::memset;
(memset_ptr)(ptr, 0, n);
#else
volatile uint8_t* p = reinterpret_cast<volatile uint8_t*>(ptr);
for(size_t i = 0; i != n; ++i)
p[i] = 0;
#endif
}
uint32_t OS::get_process_id()
{
#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
return ::getpid();
#elif defined(BOTAN_TARGET_OS_HAS_WIN32)
return ::GetCurrentProcessId();
#elif defined(BOTAN_TARGET_OS_IS_INCLUDEOS) || defined(BOTAN_TARGET_OS_IS_LLVM) || defined(BOTAN_TARGET_OS_IS_NONE)
return 0; // truly no meaningful value
#else
#error "Missing get_process_id"
#endif
}
unsigned long OS::get_auxval(unsigned long id)
{
#if defined(BOTAN_TARGET_OS_HAS_GETAUXVAL)
return ::getauxval(id);
#elif defined(BOTAN_TARGET_OS_IS_ANDROID) && defined(BOTAN_TARGET_ARCH_IS_ARM32)
if(id == 0)
return 0;
char **p = environ;
while(*p++ != nullptr)
;
Elf32_auxv_t *e = reinterpret_cast<Elf32_auxv_t*>(p);
while(e != nullptr)
{
if(e->a_type == id)
return e->a_un.a_val;
e++;
}
return 0;
#elif defined(BOTAN_TARGET_OS_HAS_ELF_AUX_INFO)
unsigned long auxinfo = 0;
::elf_aux_info(id, &auxinfo, sizeof(auxinfo));
return auxinfo;
#else
BOTAN_UNUSED(id);
return 0;
#endif
}
bool OS::running_in_privileged_state()
{
#if defined(AT_SECURE)
return OS::get_auxval(AT_SECURE) != 0;
#elif defined(BOTAN_TARGET_OS_HAS_POSIX1)
return (::getuid() != ::geteuid()) || (::getgid() != ::getegid());
#else
return false;
#endif
}
uint64_t OS::get_cpu_cycle_counter()
{
uint64_t rtc = 0;
#if defined(BOTAN_TARGET_OS_HAS_WIN32)
LARGE_INTEGER tv;
::QueryPerformanceCounter(&tv);
rtc = tv.QuadPart;
#elif defined(BOTAN_USE_GCC_INLINE_ASM)
#if defined(BOTAN_TARGET_CPU_IS_X86_FAMILY)
if(CPUID::has_rdtsc())
{
uint32_t rtc_low = 0, rtc_high = 0;
asm volatile("rdtsc" : "=d" (rtc_high), "=a" (rtc_low));
rtc = (static_cast<uint64_t>(rtc_high) << 32) | rtc_low;
}
#elif defined(BOTAN_TARGET_ARCH_IS_PPC64)
for(;;)
{
uint32_t rtc_low = 0, rtc_high = 0, rtc_high2 = 0;
asm volatile("mftbu %0" : "=r" (rtc_high));
asm volatile("mftb %0" : "=r" (rtc_low));
asm volatile("mftbu %0" : "=r" (rtc_high2));
if(rtc_high == rtc_high2)
{
rtc = (static_cast<uint64_t>(rtc_high) << 32) | rtc_low;
break;
}
}
#elif defined(BOTAN_TARGET_ARCH_IS_ALPHA)
asm volatile("rpcc %0" : "=r" (rtc));
// OpenBSD does not trap access to the %tick register
#elif defined(BOTAN_TARGET_ARCH_IS_SPARC64) && !defined(BOTAN_TARGET_OS_IS_OPENBSD)
asm volatile("rd %%tick, %0" : "=r" (rtc));
#elif defined(BOTAN_TARGET_ARCH_IS_IA64)
asm volatile("mov %0=ar.itc" : "=r" (rtc));
#elif defined(BOTAN_TARGET_ARCH_IS_S390X)
asm volatile("stck 0(%0)" : : "a" (&rtc) : "memory", "cc");
#elif defined(BOTAN_TARGET_ARCH_IS_HPPA)
asm volatile("mfctl 16,%0" : "=r" (rtc)); // 64-bit only?
#else
//#warning "OS::get_cpu_cycle_counter not implemented"
#endif
#endif
return rtc;
}
size_t OS::get_cpu_total()
{
#if defined(BOTAN_TARGET_OS_HAS_POSIX1) && defined(_SC_NPROCESSORS_CONF)
const long res = ::sysconf(_SC_NPROCESSORS_CONF);
if(res > 0)
return static_cast<size_t>(res);
#endif
#if defined(BOTAN_TARGET_OS_HAS_THREADS)
return static_cast<size_t>(std::thread::hardware_concurrency());
#else
return 1;
#endif
}
size_t OS::get_cpu_available()
{
#if defined(BOTAN_TARGET_OS_HAS_POSIX1) && defined(_SC_NPROCESSORS_ONLN)
const long res = ::sysconf(_SC_NPROCESSORS_ONLN);
if(res > 0)
return static_cast<size_t>(res);
#endif
return OS::get_cpu_total();
}
uint64_t OS::get_high_resolution_clock()
{
if(uint64_t cpu_clock = OS::get_cpu_cycle_counter())
return cpu_clock;
#if defined(BOTAN_TARGET_OS_IS_EMSCRIPTEN)
return emscripten_get_now();
#endif
/*
If we got here either we either don't have an asm instruction
above, or (for x86) RDTSC is not available at runtime. Try some
clock_gettimes and return the first one that works, or otherwise
fall back to std::chrono.
*/
#if defined(BOTAN_TARGET_OS_HAS_CLOCK_GETTIME)
// The ordering here is somewhat arbitrary...
const clockid_t clock_types[] = {
#if defined(CLOCK_MONOTONIC_HR)
CLOCK_MONOTONIC_HR,
#endif
#if defined(CLOCK_MONOTONIC_RAW)
CLOCK_MONOTONIC_RAW,
#endif
#if defined(CLOCK_MONOTONIC)
CLOCK_MONOTONIC,
#endif
#if defined(CLOCK_PROCESS_CPUTIME_ID)
CLOCK_PROCESS_CPUTIME_ID,
#endif
#if defined(CLOCK_THREAD_CPUTIME_ID)
CLOCK_THREAD_CPUTIME_ID,
#endif
};
for(clockid_t clock : clock_types)
{
struct timespec ts;
if(::clock_gettime(clock, &ts) == 0)
{
return (static_cast<uint64_t>(ts.tv_sec) * 1000000000) + static_cast<uint64_t>(ts.tv_nsec);
}
}
#endif
// Plain C++11 fallback
auto now = std::chrono::high_resolution_clock::now().time_since_epoch();
return std::chrono::duration_cast<std::chrono::nanoseconds>(now).count();
}
uint64_t OS::get_system_timestamp_ns()
{
#if defined(BOTAN_TARGET_OS_HAS_CLOCK_GETTIME)
struct timespec ts;
if(::clock_gettime(CLOCK_REALTIME, &ts) == 0)
{
return (static_cast<uint64_t>(ts.tv_sec) * 1000000000) + static_cast<uint64_t>(ts.tv_nsec);
}
#endif
auto now = std::chrono::system_clock::now().time_since_epoch();
return std::chrono::duration_cast<std::chrono::nanoseconds>(now).count();
}
size_t OS::system_page_size()
{
const size_t default_page_size = 4096;
#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
long p = ::sysconf(_SC_PAGESIZE);
if(p > 1)
return static_cast<size_t>(p);
else
return default_page_size;
#elif defined(BOTAN_TARGET_OS_HAS_VIRTUAL_LOCK)
BOTAN_UNUSED(default_page_size);
SYSTEM_INFO sys_info;
::GetSystemInfo(&sys_info);
return sys_info.dwPageSize;
#else
return default_page_size;
#endif
}
size_t OS::get_memory_locking_limit()
{
#if defined(BOTAN_TARGET_OS_HAS_POSIX1) && defined(BOTAN_TARGET_OS_HAS_POSIX_MLOCK) && defined(RLIMIT_MEMLOCK)
/*
* If RLIMIT_MEMLOCK is not defined, likely the OS does not support
* unprivileged mlock calls.
*
* Linux defaults to only 64 KiB of mlockable memory per process
* (too small) but BSDs offer a small fraction of total RAM (more
* than we need). Bound the total mlock size to 512 KiB which is
* enough to run the entire test suite without spilling to non-mlock
* memory (and thus presumably also enough for many useful
* programs), but small enough that we should not cause problems
* even if many processes are mlocking on the same machine.
*/
const size_t user_req = read_env_variable_sz("BOTAN_MLOCK_POOL_SIZE", BOTAN_MLOCK_ALLOCATOR_MAX_LOCKED_KB);
const size_t mlock_requested = std::min<size_t>(user_req, BOTAN_MLOCK_ALLOCATOR_MAX_LOCKED_KB);
if(mlock_requested > 0)
{
struct ::rlimit limits;
::getrlimit(RLIMIT_MEMLOCK, &limits);
if(limits.rlim_cur < limits.rlim_max)
{
limits.rlim_cur = limits.rlim_max;
::setrlimit(RLIMIT_MEMLOCK, &limits);
::getrlimit(RLIMIT_MEMLOCK, &limits);
}
return std::min<size_t>(limits.rlim_cur, mlock_requested * 1024);
}
#elif defined(BOTAN_TARGET_OS_HAS_VIRTUAL_LOCK)
SIZE_T working_min = 0, working_max = 0;
if(!::GetProcessWorkingSetSize(::GetCurrentProcess(), &working_min, &working_max))
{
return 0;
}
// According to Microsoft MSDN:
// The maximum number of pages that a process can lock is equal to the number of pages in its minimum working set minus a small overhead
// In the book "Windows Internals Part 2": the maximum lockable pages are minimum working set size - 8 pages
// But the information in the book seems to be inaccurate/outdated
// I've tested this on Windows 8.1 x64, Windows 10 x64 and Windows 7 x86
// On all three OS the value is 11 instead of 8
const size_t overhead = OS::system_page_size() * 11;
if(working_min > overhead)
{
const size_t lockable_bytes = working_min - overhead;
return std::min<size_t>(lockable_bytes, BOTAN_MLOCK_ALLOCATOR_MAX_LOCKED_KB * 1024);
}
#endif
// Not supported on this platform
return 0;
}
bool OS::read_env_variable(std::string& value_out, const std::string& name)
{
value_out = "";
if(running_in_privileged_state())
return false;
#if defined(BOTAN_TARGET_OS_HAS_WIN32) && defined(BOTAN_BUILD_COMPILER_IS_MSVC)
char val[128] = { 0 };
size_t req_size = 0;
if(getenv_s(&req_size, val, sizeof(val), name.c_str()) == 0)
{
value_out = std::string(val, req_size);
return true;
}
#else
if(const char* val = std::getenv(name.c_str()))
{
value_out = val;
return true;
}
#endif
return false;
}
size_t OS::read_env_variable_sz(const std::string& name, size_t def)
{
std::string value;
if(read_env_variable(value, name))
{
try
{
const size_t val = std::stoul(value, nullptr);
return val;
}
catch(std::exception&) { /* ignore it */ }
}
return def;
}
#if defined(BOTAN_TARGET_OS_HAS_POSIX1) && defined(BOTAN_TARGET_OS_HAS_POSIX_MLOCK)
namespace {
int get_locked_fd()
{
#if defined(BOTAN_TARGET_OS_IS_IOS) || defined(BOTAN_TARGET_OS_IS_MACOS)
// On Darwin, tagging anonymous pages allows vmmap to track these.
// Allowed from 240 to 255 for userland applications
static constexpr int default_locked_fd = 255;
int locked_fd = default_locked_fd;
if(size_t locked_fdl = OS::read_env_variable_sz("BOTAN_LOCKED_FD", default_locked_fd))
{
if(locked_fdl < 240 || locked_fdl > 255)
{
locked_fdl = default_locked_fd;
}
locked_fd = static_cast<int>(locked_fdl);
}
return VM_MAKE_TAG(locked_fd);
#else
return -1;
#endif
}
}
#endif
std::vector<void*> OS::allocate_locked_pages(size_t count)
{
std::vector<void*> result;
#if (defined(BOTAN_TARGET_OS_HAS_POSIX1) && defined(BOTAN_TARGET_OS_HAS_POSIX_MLOCK)) || defined(BOTAN_TARGET_OS_HAS_VIRTUAL_LOCK)
result.reserve(count);
const size_t page_size = OS::system_page_size();
#if defined(BOTAN_TARGET_OS_HAS_POSIX1) && defined(BOTAN_TARGET_OS_HAS_POSIX_MLOCK)
static const int locked_fd = get_locked_fd();
#endif
for(size_t i = 0; i != count; ++i)
{
void* ptr = nullptr;
#if defined(BOTAN_TARGET_OS_HAS_POSIX1) && defined(BOTAN_TARGET_OS_HAS_POSIX_MLOCK)
#if !defined(MAP_ANONYMOUS)
#define MAP_ANONYMOUS MAP_ANON
#endif
#if !defined(MAP_NOCORE)
#if defined(MAP_CONCEAL)
#define MAP_NOCORE MAP_CONCEAL
#else
#define MAP_NOCORE 0
#endif
#endif
#if !defined(PROT_MAX)
#define PROT_MAX(p) 0
#endif
const int pflags = PROT_READ | PROT_WRITE;
ptr = ::mmap(nullptr, 3*page_size,
pflags | PROT_MAX(pflags),
MAP_ANONYMOUS | MAP_PRIVATE | MAP_NOCORE,
/*fd=*/locked_fd, /*offset=*/0);
if(ptr == MAP_FAILED)
{
continue;
}
// lock the data page
if(::mlock(static_cast<uint8_t*>(ptr) + page_size, page_size) != 0)
{
::munmap(ptr, 3*page_size);
continue;
}
#if defined(MADV_DONTDUMP)
// we ignore errors here, as DONTDUMP is just a bonus
::madvise(static_cast<uint8_t*>(ptr) + page_size, page_size, MADV_DONTDUMP);
#endif
#elif defined(BOTAN_TARGET_OS_HAS_VIRTUAL_LOCK)
ptr = ::VirtualAlloc(nullptr, 3*page_size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
if(ptr == nullptr)
continue;
if(::VirtualLock(static_cast<uint8_t*>(ptr) + page_size, page_size) == 0)
{
::VirtualFree(ptr, 0, MEM_RELEASE);
continue;
}
#endif
std::memset(ptr, 0, 3*page_size); // zero data page and both guard pages
// Make guard page preceeding the data page
page_prohibit_access(static_cast<uint8_t*>(ptr));
// Make guard page following the data page
page_prohibit_access(static_cast<uint8_t*>(ptr) + 2*page_size);
result.push_back(static_cast<uint8_t*>(ptr) + page_size);
}
#else
BOTAN_UNUSED(count);
#endif
return result;
}
void OS::page_allow_access(void* page)
{
#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
const size_t page_size = OS::system_page_size();
::mprotect(page, page_size, PROT_READ | PROT_WRITE);
#elif defined(BOTAN_TARGET_OS_HAS_VIRTUAL_LOCK)
const size_t page_size = OS::system_page_size();
DWORD old_perms = 0;
::VirtualProtect(page, page_size, PAGE_READWRITE, &old_perms);
BOTAN_UNUSED(old_perms);
#else
BOTAN_UNUSED(page);
#endif
}
void OS::page_prohibit_access(void* page)
{
#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
const size_t page_size = OS::system_page_size();
::mprotect(page, page_size, PROT_NONE);
#elif defined(BOTAN_TARGET_OS_HAS_VIRTUAL_LOCK)
const size_t page_size = OS::system_page_size();
DWORD old_perms = 0;
::VirtualProtect(page, page_size, PAGE_NOACCESS, &old_perms);
BOTAN_UNUSED(old_perms);
#else
BOTAN_UNUSED(page);
#endif
}
void OS::free_locked_pages(const std::vector<void*>& pages)
{
const size_t page_size = OS::system_page_size();
for(size_t i = 0; i != pages.size(); ++i)
{
void* ptr = pages[i];
secure_scrub_memory(ptr, page_size);
// ptr points to the data page, guard pages are before and after
page_allow_access(static_cast<uint8_t*>(ptr) - page_size);
page_allow_access(static_cast<uint8_t*>(ptr) + page_size);
#if defined(BOTAN_TARGET_OS_HAS_POSIX1) && defined(BOTAN_TARGET_OS_HAS_POSIX_MLOCK)
::munlock(ptr, page_size);
::munmap(static_cast<uint8_t*>(ptr) - page_size, 3*page_size);
#elif defined(BOTAN_TARGET_OS_HAS_VIRTUAL_LOCK)
::VirtualUnlock(ptr, page_size);
::VirtualFree(static_cast<uint8_t*>(ptr) - page_size, 0, MEM_RELEASE);
#endif
}
}
#if defined(BOTAN_TARGET_OS_HAS_POSIX1) && !defined(BOTAN_TARGET_OS_IS_EMSCRIPTEN)
namespace {
static ::sigjmp_buf g_sigill_jmp_buf;
void botan_sigill_handler(int)
{
siglongjmp(g_sigill_jmp_buf, /*non-zero return value*/1);
}
}
#endif
int OS::run_cpu_instruction_probe(std::function<int ()> probe_fn)
{
volatile int probe_result = -3;
#if defined(BOTAN_TARGET_OS_HAS_POSIX1) && !defined(BOTAN_TARGET_OS_IS_EMSCRIPTEN)
struct sigaction old_sigaction;
struct sigaction sigaction;
sigaction.sa_handler = botan_sigill_handler;
sigemptyset(&sigaction.sa_mask);
sigaction.sa_flags = 0;
int rc = ::sigaction(SIGILL, &sigaction, &old_sigaction);
if(rc != 0)
throw System_Error("run_cpu_instruction_probe sigaction failed", errno);
rc = sigsetjmp(g_sigill_jmp_buf, /*save sigs*/1);
if(rc == 0)
{
// first call to sigsetjmp
probe_result = probe_fn();
}
else if(rc == 1)
{
// non-local return from siglongjmp in signal handler: return error
probe_result = -1;
}
// Restore old SIGILL handler, if any
rc = ::sigaction(SIGILL, &old_sigaction, nullptr);
if(rc != 0)
throw System_Error("run_cpu_instruction_probe sigaction restore failed", errno);
#else
BOTAN_UNUSED(probe_fn);
#endif
return probe_result;
}
std::unique_ptr<OS::Echo_Suppression> OS::suppress_echo_on_terminal()
{
#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
class POSIX_Echo_Suppression : public Echo_Suppression
{
public:
POSIX_Echo_Suppression()
{
m_stdin_fd = fileno(stdin);
if(::tcgetattr(m_stdin_fd, &m_old_termios) != 0)
throw System_Error("Getting terminal status failed", errno);
struct termios noecho_flags = m_old_termios;
noecho_flags.c_lflag &= ~ECHO;
noecho_flags.c_lflag |= ECHONL;
if(::tcsetattr(m_stdin_fd, TCSANOW, &noecho_flags) != 0)
throw System_Error("Clearing terminal echo bit failed", errno);
}
void reenable_echo() override
{
if(m_stdin_fd > 0)
{
if(::tcsetattr(m_stdin_fd, TCSANOW, &m_old_termios) != 0)
throw System_Error("Restoring terminal echo bit failed", errno);
m_stdin_fd = -1;
}
}
~POSIX_Echo_Suppression()
{
try
{
reenable_echo();
}
catch(...)
{
}
}
private:
int m_stdin_fd;
struct termios m_old_termios;
};
return std::unique_ptr<Echo_Suppression>(new POSIX_Echo_Suppression);
#elif defined(BOTAN_TARGET_OS_HAS_WIN32)
class Win32_Echo_Suppression : public Echo_Suppression
{
public:
Win32_Echo_Suppression()
{
m_input_handle = ::GetStdHandle(STD_INPUT_HANDLE);
if(::GetConsoleMode(m_input_handle, &m_console_state) == 0)
throw System_Error("Getting console mode failed", ::GetLastError());
DWORD new_mode = ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT;
if(::SetConsoleMode(m_input_handle, new_mode) == 0)
throw System_Error("Setting console mode failed", ::GetLastError());
}
void reenable_echo() override
{
if(m_input_handle != INVALID_HANDLE_VALUE)
{
if(::SetConsoleMode(m_input_handle, m_console_state) == 0)
throw System_Error("Setting console mode failed", ::GetLastError());
m_input_handle = INVALID_HANDLE_VALUE;
}
}
~Win32_Echo_Suppression()
{
try
{
reenable_echo();
}
catch(...)
{
}
}
private:
HANDLE m_input_handle;
DWORD m_console_state;
};
return std::unique_ptr<Echo_Suppression>(new Win32_Echo_Suppression);
#else
// Not supported on this platform, return null
return std::unique_ptr<Echo_Suppression>();
#endif
}
}