Non-SFI mode: Implement nacl_irt_random only for nacl_helper_nonsfi.

src/nonsfi/irt/irt_interfaces.c

 /*
  * Copyright (c) 2013 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "native_client/src/nonsfi/irt/irt_interfaces.h"
 
 #include <assert.h>
 #include <errno.h>
@@ skipping 20 matching lines @@
 #include "native_client/src/public/irt_core.h"
 #include "native_client/src/trusted/service_runtime/include/machine/_types.h"
 #include "native_client/src/trusted/service_runtime/include/sys/mman.h"
 #include "native_client/src/trusted/service_runtime/include/sys/stat.h"
 #include "native_client/src/trusted/service_runtime/include/sys/time.h"
 #include "native_client/src/trusted/service_runtime/include/sys/unistd.h"
 #include "native_client/src/untrusted/irt/irt.h"
 #include "native_client/src/untrusted/irt/irt_dev.h"
 #include "native_client/src/untrusted/irt/irt_interfaces.h"
 
+#if defined(__native_client__)
+#include "native_client/src/nonsfi/irt/irt_random.h"
+#endif
+
 /*
  * This is an implementation of NaCl's IRT interfaces that runs
  * outside of the NaCl sandbox.
  *
  * This allows PNaCl to be used as a portability layer without the
  * SFI-based sandboxing.  PNaCl pexes can be translated to
  * non-SFI-sandboxed native code and linked against this IRT
  * implementation.
  */
 
@@ skipping 373 matching lines @@
 static int futex_wake(volatile int *addr, int nwake, int *count) {
   int result = syscall(__NR_futex, addr, FUTEX_WAKE | FUTEX_PRIVATE_FLAG,
                        nwake, 0, 0, 0);
   if (result < 0)
     return errno;
   *count = result;
   return 0;
 }
 #endif
 
+#if defined(__native_client__)
+static int urandom_fd = -1;

[Mark Seaborn, 2014/10/30 18:58:30]

Style nit: Add "g_" prefix to the name

[hidehiko, 2014/10/31 14:03:52]

Done (in irt_random.c).

+
+void nonsfi_set_urandom_fd(int fd) {
+  urandom_fd = fd;
+}
+
+static int irt_get_random_bytes(void *buf, size_t count, size_t *nread) {

[Mark Seaborn, 2014/10/30 18:58:30]

It's rather unfortunate that this isn't tested on the NaCl side.

One of the goals in the newlib switch was to improve testing of IRT interface
implementations, because moving IRT interface implementations to the NaCl side
allows us to run NaCl-side tests against those implementations.

So, could you add a small amount of plumbing so that we can enable
run_random_test_irt to cover this code?  i.e. If urandom_fd == -1, try to open
/dev/urandom.

(An alternative would be to implement irt_random on the Chromium side.  That
would be reasonable, since irt_random is very simple to implement.  However,
implementing irt_random on the NaCl side is more usable since the code can be
reused for the unsandboxed-PNaCl use case.)

[hidehiko, 2014/10/31 14:03:52]

Done.

+  int result = read(urandom_fd, buf, count);
+  if (result < 0)
+    return errno;
+  *nread = result;
+  return 0;
+}
+#endif
+
 #if defined(__linux__) || defined(__native_client__)
 static int irt_clock_getres(nacl_irt_clockid_t clk_id,
                             struct timespec *time_nacl) {
   struct timespec time;
   int result = check_error(clock_getres(clk_id, &time));
   /*
    * The timespec pointer is allowed to be NULL for clock_getres() though
    * not for clock_gettime().
    */
   if (time_nacl != NULL)
@@ skipping 148 matching lines @@
 };
 #elif !defined(__native_client__)
 DEFINE_STUB(futex_wait_abs)
 DEFINE_STUB(futex_wake)
 const struct nacl_irt_futex nacl_irt_futex = {
   USE_STUB(nacl_irt_futex, futex_wait_abs),
   USE_STUB(nacl_irt_futex, futex_wake),
 };
 #endif
 
+#if defined(__native_client__)
+const struct nacl_irt_random nacl_irt_random = {
+  irt_get_random_bytes,
+};
+#endif
+
 #if defined(__linux__) || defined(__native_client__)
 const struct nacl_irt_clock nacl_irt_clock = {
   irt_clock_getres,
   irt_clock_gettime,
 };
 #endif
 
 DEFINE_STUB(utimes)
 const struct nacl_irt_dev_filename nacl_irt_dev_filename = {
   irt_open,
@@ skipping 31 matching lines @@
 };
 #endif
 
 static const struct nacl_irt_interface irt_interfaces[] = {
   { NACL_IRT_BASIC_v0_1, &nacl_irt_basic, sizeof(nacl_irt_basic), NULL },
   { NACL_IRT_FDIO_v0_1, &nacl_irt_fdio, sizeof(nacl_irt_fdio), NULL },
   { NACL_IRT_MEMORY_v0_3, &nacl_irt_memory, sizeof(nacl_irt_memory), NULL },
   { NACL_IRT_TLS_v0_1, &nacl_irt_tls, sizeof(nacl_irt_tls), NULL },
   { NACL_IRT_THREAD_v0_1, &nacl_irt_thread, sizeof(nacl_irt_thread), NULL },
   { NACL_IRT_FUTEX_v0_1, &nacl_irt_futex, sizeof(nacl_irt_futex), NULL },
+#if defined(__native_client__)
+  { NACL_IRT_RANDOM_v0_1, &nacl_irt_random, sizeof(nacl_irt_random), NULL },
+#endif
 #if defined(__linux__) || defined(__native_client__)
   { NACL_IRT_CLOCK_v0_1, &nacl_irt_clock, sizeof(nacl_irt_clock), NULL },
 #endif
   { NACL_IRT_DEV_FILENAME_v0_3, &nacl_irt_dev_filename,
     sizeof(nacl_irt_dev_filename), NULL },
   { NACL_IRT_DEV_GETPID_v0_1, &nacl_irt_dev_getpid,
     sizeof(nacl_irt_dev_getpid), NULL },
 #if defined(__native_client__)
   { NACL_IRT_EXCEPTION_HANDLING_v0_1, &nacl_irt_exception_handling,
     sizeof(nacl_irt_exception_handling), NULL},
@@ skipping 60 matching lines @@
   nacl_entry_func_t entry_func =
 #if defined(__APPLE__)
     _start;
 #else
     _user_start;
 #endif
 
   return nacl_irt_nonsfi_entry(argc, argv, environ, entry_func);
 }
 #endif