[libcxx] r223068 - libc++: add NaCl and PNaCl support for std::random_device
JF Bastien
jfb at google.com
Mon Dec 1 11:19:55 PST 2014
Author: jfb
Date: Mon Dec 1 13:19:55 2014
New Revision: 223068
URL: http://llvm.org/viewvc/llvm-project?rev=223068&view=rev
Log:
libc++: add NaCl and PNaCl support for std::random_device
Summary:
The NaCl sandbox doesn't allow opening files under /dev, but it offers an API which provides the same capabilities. This is the same random device emulation that nacl_io performs for POSIX support, but nacl_io is an optional library so libc++ can't assume that device emulation will be performed. Note that NaCl only supports /dev/urandom, not /dev/random.
This patch also cleans up some of the preprocessor #endif, and fixes the test for Win32 (it accepts any token, and would therefore never throw regardless of the token provided).
Test Plan: ninja check-libcxx
Reviewers: dschuff, mclow.lists, danalbert
Subscribers: jfb, cfe-commits
Differential Revision: http://reviews.llvm.org/D6442
Modified:
libcxx/trunk/include/__config
libcxx/trunk/include/random
libcxx/trunk/src/random.cpp
libcxx/trunk/test/numerics/rand/rand.device/ctor.pass.cpp
Modified: libcxx/trunk/include/__config
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/__config?rev=223068&r1=223067&r2=223068&view=diff
==============================================================================
--- libcxx/trunk/include/__config (original)
+++ libcxx/trunk/include/__config Mon Dec 1 13:19:55 2014
@@ -111,6 +111,13 @@
# endif
#endif // __sun__
+#if defined(__native_client__)
+ // NaCl's sandbox (which PNaCl also runs in) doesn't allow filesystem access,
+ // including accesses to the special files under /dev. C++11's
+ // std::random_device is instead exposed through a NaCl syscall.
+# define _LIBCPP_USING_NACL_RANDOM
+#endif // defined(__native_client__)
+
#if !defined(_LIBCPP_LITTLE_ENDIAN) || !defined(_LIBCPP_BIG_ENDIAN)
# include <endian.h>
# if __BYTE_ORDER == __LITTLE_ENDIAN
Modified: libcxx/trunk/include/random
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/random?rev=223068&r1=223067&r2=223068&view=diff
==============================================================================
--- libcxx/trunk/include/random (original)
+++ libcxx/trunk/include/random Mon Dec 1 13:19:55 2014
@@ -3475,9 +3475,9 @@ typedef shuffle_order_engine<minstd_rand
class _LIBCPP_TYPE_VIS random_device
{
-#if !defined(_WIN32)
+#if !(defined(_WIN32) || defined(_LIBCPP_USING_NACL_RANDOM))
int __f_;
-#endif // defined(_WIN32)
+#endif // !(defined(_WIN32) || defined(_LIBCPP_USING_NACL_RANDOM))
public:
// types
typedef unsigned result_type;
Modified: libcxx/trunk/src/random.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/src/random.cpp?rev=223068&r1=223067&r2=223068&view=diff
==============================================================================
--- libcxx/trunk/src/random.cpp (original)
+++ libcxx/trunk/src/random.cpp Mon Dec 1 13:19:55 2014
@@ -11,23 +11,27 @@
// Must be defined before including stdlib.h to enable rand_s().
#define _CRT_RAND_S
#include <stdio.h>
-#endif
+#endif // defined(_WIN32)
#include "random"
#include "system_error"
-#ifdef __sun__
+#if defined(__sun__)
#define rename solaris_headers_are_broken
-#endif
+#endif // defined(__sun__)
#if !defined(_WIN32)
#include <fcntl.h>
#include <unistd.h>
-#endif // defined(_WIN32)
+#endif // !defined(_WIN32)
#include <errno.h>
+#if defined(_LIBCPP_USING_NACL_RANDOM)
+#include <nacl/nacl_random.h>
+#endif // defined(_LIBCPP_USING_NACL_RANDOM)
_LIBCPP_BEGIN_NAMESPACE_STD
#if defined(_WIN32)
+
random_device::random_device(const string&)
{
}
@@ -45,7 +49,39 @@ random_device::operator()()
__throw_system_error(err, "random_device rand_s failed.");
return r;
}
-#else
+
+#elif defined(_LIBCPP_USING_NACL_RANDOM)
+
+random_device::random_device(const string& __token)
+{
+ if (__token != "/dev/urandom")
+ __throw_system_error(ENOENT, ("random device not supported " + __token).c_str());
+ int error = nacl_secure_random_init();
+ if (error)
+ __throw_system_error(error, ("random device failed to open " + __token).c_str());
+}
+
+random_device::~random_device()
+{
+}
+
+unsigned
+random_device::operator()()
+{
+ unsigned r;
+ size_t n = sizeof(r);
+ char* p = reinterpret_cast<char*>(&r);
+ size_t bytes_written;
+ int error = nacl_secure_random(&r, n, &bytes_written);
+ if (error != 0)
+ __throw_system_error(error, "random_device failed getting bytes");
+ else if (bytes_written != n)
+ __throw_runtime_error("random_device failed to obtain enough bytes");
+ return r;
+}
+
+#else // !defined(_WIN32) && !defined(_LIBCPP_USING_NACL_RANDOM)
+
random_device::random_device(const string& __token)
: __f_(open(__token.c_str(), O_RDONLY))
{
@@ -80,7 +116,8 @@ random_device::operator()()
}
return r;
}
-#endif // defined(_WIN32)
+
+#endif // defined(_WIN32) || defined(_LIBCPP_USING_NACL_RANDOM)
double
random_device::entropy() const _NOEXCEPT
Modified: libcxx/trunk/test/numerics/rand/rand.device/ctor.pass.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/numerics/rand/rand.device/ctor.pass.cpp?rev=223068&r1=223067&r2=223068&view=diff
==============================================================================
--- libcxx/trunk/test/numerics/rand/rand.device/ctor.pass.cpp (original)
+++ libcxx/trunk/test/numerics/rand/rand.device/ctor.pass.cpp Mon Dec 1 13:19:55 2014
@@ -11,39 +11,75 @@
// class random_device;
-// explicit random_device(const string& token = "/dev/urandom");
+// explicit random_device(const string& token = implementation-defined);
+
+// For the following ctors, the standard states: "The semantics and default
+// value of the token parameter are implementation-defined". Implementations
+// therefore aren't required to accept any string, but the default shouldn't
+// throw.
#include <random>
#include <cassert>
#include <unistd.h>
-int main()
-{
- try
- {
- std::random_device r("wrong file");
- assert(false);
- }
- catch (const std::system_error& e)
- {
- }
- {
- std::random_device r;
- }
- {
- int ec;
- ec = close(STDIN_FILENO);
- assert(!ec);
- ec = close(STDOUT_FILENO);
- assert(!ec);
- ec = close(STDERR_FILENO);
- assert(!ec);
- std::random_device r;
- }
- {
- std::random_device r("/dev/urandom");;
- }
- {
- std::random_device r("/dev/random");;
- }
+bool is_valid_random_device(const std::string &token) {
+#if defined(_WIN32)
+ return true;
+#elif defined(_LIBCPP_USING_NACL_RANDOM)
+ return token == "/dev/urandom";
+#else // !defined(_WIN32) && !defined(_LIBCPP_USING_NACL_RANDOM)
+ // Not an exhaustive list: they're the only tokens that are tested below.
+ return token == "/dev/urandom" || token == "/dev/random";
+#endif // defined(_WIN32) || defined(_LIBCPP_USING_NACL_RANDOM)
+}
+
+void check_random_device_valid(const std::string &token) {
+ std::random_device r(token);
+}
+
+void check_random_device_invalid(const std::string &token) {
+ try {
+ std::random_device r(token);
+ assert(false);
+ } catch (const std::system_error &e) {
+ }
+}
+
+int main() {
+ { std::random_device r; }
+
+ {
+ int ec;
+ ec = close(STDIN_FILENO);
+ assert(!ec);
+ ec = close(STDOUT_FILENO);
+ assert(!ec);
+ ec = close(STDERR_FILENO);
+ assert(!ec);
+ std::random_device r;
+ }
+
+ {
+ std::string token = "wrong file";
+ if (is_valid_random_device(token))
+ check_random_device_valid(token);
+ else
+ check_random_device_invalid(token);
+ }
+
+ {
+ std::string token = "/dev/urandom";
+ if (is_valid_random_device(token))
+ check_random_device_valid(token);
+ else
+ check_random_device_invalid(token);
+ }
+
+ {
+ std::string token = "/dev/random";
+ if (is_valid_random_device(token))
+ check_random_device_valid(token);
+ else
+ check_random_device_invalid(token);
+ }
}
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