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- /* boost uuid/detail/random_provider_posix implementation
- *
- * Copyright Jens Maurer 2000
- * Copyright 2007 Andy Tompkins.
- * Copyright Steven Watanabe 2010-2011
- * Copyright 2017 James E. King III
- *
- * Distributed under the Boost Software License, Version 1.0. (See
- * accompanying file LICENSE_1_0.txt or copy at
- * https://www.boost.org/LICENSE_1_0.txt)
- *
- * $Id$
- */
- #include <boost/config.hpp>
- #include <boost/core/ignore_unused.hpp>
- #include <boost/move/core.hpp>
- #include <boost/throw_exception.hpp>
- #include <boost/uuid/entropy_error.hpp>
- #include <cerrno>
- #include <cstddef>
- #include <fcntl.h> // open
- #include <sys/stat.h>
- #include <sys/types.h>
- #if defined(BOOST_HAS_UNISTD_H)
- #include <unistd.h>
- #endif
- #ifndef BOOST_UUID_RANDOM_PROVIDER_POSIX_IMPL_CLOSE
- #define BOOST_UUID_RANDOM_PROVIDER_POSIX_IMPL_CLOSE ::close
- #endif
- #ifndef BOOST_UUID_RANDOM_PROVIDER_POSIX_IMPL_OPEN
- #define BOOST_UUID_RANDOM_PROVIDER_POSIX_IMPL_OPEN ::open
- #endif
- #ifndef BOOST_UUID_RANDOM_PROVIDER_POSIX_IMPL_READ
- #define BOOST_UUID_RANDOM_PROVIDER_POSIX_IMPL_READ ::read
- #endif
- namespace boost {
- namespace uuids {
- namespace detail {
- class random_provider_base
- {
- BOOST_MOVABLE_BUT_NOT_COPYABLE(random_provider_base)
- public:
- random_provider_base()
- : fd_(-1)
- {
- int flags = O_RDONLY;
- #if defined(O_CLOEXEC)
- flags |= O_CLOEXEC;
- #endif
- fd_ = BOOST_UUID_RANDOM_PROVIDER_POSIX_IMPL_OPEN("/dev/urandom", flags);
- if (BOOST_UNLIKELY(-1 == fd_))
- {
- int err = errno;
- BOOST_THROW_EXCEPTION(entropy_error(err, "open /dev/urandom"));
- }
- }
- random_provider_base(BOOST_RV_REF(random_provider_base) that) BOOST_NOEXCEPT : fd_(that.fd_)
- {
- that.fd_ = -1;
- }
- random_provider_base& operator= (BOOST_RV_REF(random_provider_base) that) BOOST_NOEXCEPT
- {
- destroy();
- fd_ = that.fd_;
- that.fd_ = -1;
- return *this;
- }
- ~random_provider_base() BOOST_NOEXCEPT
- {
- destroy();
- }
- //! Obtain entropy and place it into a memory location
- //! \param[in] buf the location to write entropy
- //! \param[in] siz the number of bytes to acquire
- void get_random_bytes(void *buf, std::size_t siz)
- {
- std::size_t offset = 0;
- while (offset < siz)
- {
- ssize_t sz = BOOST_UUID_RANDOM_PROVIDER_POSIX_IMPL_READ(
- fd_, static_cast<char *>(buf) + offset, siz - offset);
- if (BOOST_UNLIKELY(sz < 0))
- {
- int err = errno;
- if (err == EINTR)
- continue;
- BOOST_THROW_EXCEPTION(entropy_error(err, "read"));
- }
- offset += sz;
- }
- }
- private:
- void destroy() BOOST_NOEXCEPT
- {
- if (fd_ >= 0)
- {
- boost::ignore_unused(BOOST_UUID_RANDOM_PROVIDER_POSIX_IMPL_CLOSE(fd_));
- }
- }
- private:
- int fd_;
- };
- } // detail
- } // uuids
- } // boost
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