IDF release/v4.0 08219f3cf

tools/sdk/include/coap/coap2/prng.h

@@ -0,0 +1,127 @@
+/*
+ * prng.h -- Pseudo Random Numbers
+ *
+ * Copyright (C) 2010-2011 Olaf Bergmann <bergmann@tzi.org>
+ *
+ * This file is part of the CoAP library libcoap. Please see README for terms
+ * of use.
+ */
+
+/**
+ * @file prng.h
+ * @brief Pseudo Random Numbers
+ */
+
+#ifndef COAP_PRNG_H_
+#define COAP_PRNG_H_
+
+/**
+ * @defgroup prng Pseudo Random Numbers
+ * API functions for gerating pseudo random numbers
+ * @{
+ */
+
+#if defined(WITH_CONTIKI)
+#include <string.h>
+
+/**
+ * Fills \p buf with \p len random bytes. This is the default implementation for
+ * prng(). You might want to change prng() to use a better PRNG on your specific
+ * platform.
+ */
+COAP_STATIC_INLINE int
+contiki_prng_impl(unsigned char *buf, size_t len) {
+  uint16_t v = random_rand();
+  while (len > sizeof(v)) {
+    memcpy(buf, &v, sizeof(v));
+    len -= sizeof(v);
+    buf += sizeof(v);
+    v = random_rand();
+  }
+
+  memcpy(buf, &v, len);
+  return 1;
+}
+
+#define prng(Buf,Length) contiki_prng_impl((Buf), (Length))
+#define prng_init(Value) random_init((uint16_t)(Value))
+#elif defined(WITH_LWIP) && defined(LWIP_RAND)
+COAP_STATIC_INLINE int
+lwip_prng_impl(unsigned char *buf, size_t len) {
+  u32_t v = LWIP_RAND();
+  while (len > sizeof(v)) {
+    memcpy(buf, &v, sizeof(v));
+    len -= sizeof(v);
+    buf += sizeof(v);
+    v = LWIP_RAND();
+  }
+
+  memcpy(buf, &v, len);
+  return 1;
+}
+
+#define prng(Buf,Length) lwip_prng_impl((Buf), (Length))
+#define prng_init(Value)
+#elif defined(_WIN32)
+#define prng_init(Value)
+errno_t __cdecl rand_s( _Out_ unsigned int* _RandomValue );
+ /**
+ * Fills \p buf with \p len random bytes. This is the default implementation for
+ * prng(). You might want to change prng() to use a better PRNG on your specific
+ * platform.
+ */
+COAP_STATIC_INLINE int
+coap_prng_impl( unsigned char *buf, size_t len ) {
+        while ( len != 0 ) {
+                uint32_t r = 0;
+                size_t i;
+                if ( rand_s( &r ) != 0 )
+                        return 0;
+                for ( i = 0; i < len && i < 4; i++ ) {
+                        *buf++ = (uint8_t)r;
+                        r >>= 8;
+                }
+                len -= i;
+        }
+        return 1;
+}
+
+#else
+#include <stdlib.h>
+
+ /**
+ * Fills \p buf with \p len random bytes. This is the default implementation for
+ * prng(). You might want to change prng() to use a better PRNG on your specific
+ * platform.
+ */
+COAP_STATIC_INLINE int
+coap_prng_impl( unsigned char *buf, size_t len ) {
+        while ( len-- )
+                *buf++ = rand() & 0xFF;
+        return 1;
+}
+#endif
+
+
+#ifndef prng
+/**
+ * Fills \p Buf with \p Length bytes of random data.
+ *
+ * @hideinitializer
+ */
+#define prng(Buf,Length) coap_prng_impl((Buf), (Length))
+#endif
+
+#ifndef prng_init
+/**
+ * Called to set the PRNG seed. You may want to re-define this to allow for a
+ * better PRNG.
+ *
+ * @hideinitializer
+ */
+#define prng_init(Value) srand((unsigned long)(Value))
+#endif
+
+/** @} */
+
+#endif /* COAP_PRNG_H_ */