Diff: lwip/core/def.c

Revision:

0:350011bf8be7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lwip/core/def.c	Tue Nov 23 14:15:36 2010 +0000
@@ -0,0 +1,108 @@
+/**
+ * @file
+ * Common functions used throughout the stack.
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * 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. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Simon Goldschmidt
+ *
+ */
+
+#include "lwip/opt.h"
+#include "lwip/def.h"
+
+/**
+ * These are reference implementations of the byte swapping functions.
+ * Again with the aim of being simple, correct and fully portable.
+ * Byte swapping is the second thing you would want to optimize. You will
+ * need to port it to your architecture and in your cc.h:
+ * 
+ * #define LWIP_PLATFORM_BYTESWAP 1
+ * #define LWIP_PLATFORM_HTONS(x) <your_htons>
+ * #define LWIP_PLATFORM_HTONL(x) <your_htonl>
+ *
+ * Note ntohs() and ntohl() are merely references to the htonx counterparts.
+ */
+
+#if (LWIP_PLATFORM_BYTESWAP == 0) && (BYTE_ORDER == LITTLE_ENDIAN)
+
+/**
+ * Convert an u16_t from host- to network byte order.
+ *
+ * @param n u16_t in host byte order
+ * @return n in network byte order
+ */
+u16_t
+lwip_htons(u16_t n)
+{
+  return ((n & 0xff) << 8) | ((n & 0xff00) >> 8);
+}
+
+/**
+ * Convert an u16_t from network- to host byte order.
+ *
+ * @param n u16_t in network byte order
+ * @return n in host byte order
+ */
+u16_t
+lwip_ntohs(u16_t n)
+{
+  return lwip_htons(n);
+}
+
+/**
+ * Convert an u32_t from host- to network byte order.
+ *
+ * @param n u32_t in host byte order
+ * @return n in network byte order
+ */
+u32_t
+lwip_htonl(u32_t n)
+{
+  return ((n & 0xff) << 24) |
+    ((n & 0xff00) << 8) |
+    ((n & 0xff0000UL) >> 8) |
+    ((n & 0xff000000UL) >> 24);
+}
+
+/**
+ * Convert an u32_t from network- to host byte order.
+ *
+ * @param n u32_t in network byte order
+ * @return n in host byte order
+ */
+u32_t
+lwip_ntohl(u32_t n)
+{
+  return lwip_htonl(n);
+}
+
+#endif /* (LWIP_PLATFORM_BYTESWAP == 0) && (BYTE_ORDER == LITTLE_ENDIAN) */