apps/examples/random: Add a test for /dev/random

2025-10-16 22:38:41 +08:00 · 2013-10-20 11:37:56 -06:00
parent bf17953959
commit a976360e0d
9 changed files with 314 additions and 9 deletions
--- a/examples/random/random_main.c
+++ b/examples/random/random_main.c
@@ -0,0 +1,128 @@
+/****************************************************************************
+ * examples/random/random_main.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <debug.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+/* Configuration ************************************************************/
+
+#ifndef CONFIG_EXAMPLES_MAXSAMPLES
+#  define CONFIG_EXAMPLES_MAXSAMPLES 64
+#endif
+
+#ifndef CONFIG_EXAMPLES_NSAMPLES
+#  define CONFIG_EXAMPLES_NSAMPLES 8
+#endif
+
+#if CONFIG_EXAMPLES_NSAMPLES > CONFIG_EXAMPLES_MAXSAMPLES
+#  warning CONFIG_EXAMPLES_NSAMPLES > CONFIG_EXAMPLES_MAXSAMPLES
+#  undef CONFIG_EXAMPLES_NSAMPLES
+#  define CONFIG_EXAMPLES_NSAMPLES CONFIG_EXAMPLES_MAXSAMPLES
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * rand_main
+ ****************************************************************************/
+
+int rand_main(int argc, char *argv[])
+{
+  uint32_t buffer[CONFIG_EXAMPLES_MAXSAMPLES];
+  int nsamples = CONFIG_EXAMPLES_NSAMPLES;
+  ssize_t nread;
+  int fd;
+
+  /* One argument is possible... the number of samples to collect */
+
+  if (argc > 1)
+    {
+      nsamples  = atoi(argv[1]);
+    }
+
+  /* Clip the numer of samples to the configured buffer size */
+
+  if (nsamples > CONFIG_EXAMPLES_MAXSAMPLES)
+    {
+      nsamples = CONFIG_EXAMPLES_MAXSAMPLES;
+    }
+
+  /* Open /dev/random */
+
+  fd = open("/dev/random", O_RDONLY);
+  if (fd < 0)
+    {
+      int errcode = errno;
+      fprintf(stderr, "ERROR: Failed to open /dev/random: %d\n", errcode);
+      exit(EXIT_FAILURE);
+    }
+
+  /* Read the requested number of samples */
+
+  printf("Reading %d random numbers\n", nsamples);
+  nread = read(fd, buffer, nsamples * sizeof(uint32_t));
+  if (nread < 0)
+    {
+      int errcode = errno;
+      fprintf(stderr, "ERROR: Read from /dev/randon failed: %d\n", errcode);
+      (void)close(fd);
+      exit(EXIT_FAILURE);
+    }
+
+  /* Dump the sample buffer */
+
+  lib_dumpbuffer("Random values", (FAR const uint8_t*)buffer, nread);
+  (void)close(fd);
+  return EXIT_SUCCESS;
+}
+