include: Add header for endianness

This adds a header for dealing with endianness in ouroboros. It is
extracted from the byte_order header in the library (which now
includes this header). It also exposes the functions ntohl, ntohll,
htonl and htonll, necessary for converting 32 and 64 bit values for
storage and retrieval from the RIB (which should store multi-byte
values in network byte order).

2 files changed, 155 insertions, 0 deletions

diff --git a/include/ouroboros/CMakeLists.txt b/include/ouroboros/CMakeLists.txt
index 41feb65e..d1a3166c 100644
--- a/include/ouroboros/CMakeLists.txt
+++ b/include/ouroboros/CMakeLists.txt
@@ -5,6 +5,7 @@ configure_file(
 set(HEADER_FILES
   cdap.h
   dev.h
+  endian.h
   errno.h
   fcntl.h
   fqueue.h
diff --git a/include/ouroboros/endian.h b/include/ouroboros/endian.h
new file mode 100644
index 00000000..c6b0d80a
--- /dev/null
+++ b/include/ouroboros/endian.h
@@ -0,0 +1,154 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2017
+ *
+ * Endianness
+ *
+ *    Dimitri Staessens <dimitri.staessens@intec.ugent.be>
+ *
+ * This implementation is adapted and redistributed from the RHASH
+ * project
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * version 2.1 as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+/*
+ * byte_order.h - byte order related platform dependent routines,
+ *
+ * Copyright: 2008-2012 Aleksey Kravchenko <rhash.admin@gmail.com>
+ *
+ * Permission is hereby granted,  free of charge,  to any person  obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction,  including without limitation
+ * the rights to  use, copy, modify,  merge, publish, distribute, sublicense,
+ * and/or sell copies  of  the Software,  and to permit  persons  to whom the
+ * Software is furnished to do so.
+ *
+ * This program  is  distributed  in  the  hope  that it will be useful,  but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  Use this program  at  your own risk!
+ */
+
+#ifndef OUROBOROS_ENDIAN_H
+#define OUROBOROS_ENDIAN_H
+
+#include <stdint.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+#ifdef __GLIBC__
+#include <endian.h>
+#elif defined(__FreeBSD__)
+#include <sys/endian.h>
+#endif
+
+/* if x86 compatible cpu */
+#if defined(i386) || defined(__i386__) || defined(__i486__) || \
+        defined(__i586__) || defined(__i686__) || defined(__pentium__) || \
+        defined(__pentiumpro__) || defined(__pentium4__) ||             \
+        defined(__nocona__) || defined(prescott) || defined(__core2__) || \
+        defined(__k6__) || defined(__k8__) || defined(__athlon__) ||    \
+        defined(__amd64) || defined(__amd64__) ||                       \
+        defined(__x86_64) || defined(__x86_64__) || defined(_M_IX86) || \
+        defined(_M_AMD64) || defined(_M_IA64) || defined(_M_X64)
+/* detect if x86-64 instruction set is supported */
+# if defined(_LP64) || defined(__LP64__) || defined(__x86_64) || \
+        defined(__x86_64__) || defined(_M_AMD64) || defined(_M_X64)
+#  define CPU_X64
+# else
+#  define CPU_IA32
+# endif
+#endif
+
+/* detect CPU endianness */
+#if (defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && \
+     __BYTE_ORDER == __LITTLE_ENDIAN) ||                  \
+        defined(CPU_IA32) || defined(CPU_X64) ||                        \
+        defined(__ia64) || defined(__ia64__) || defined(__alpha__) ||   \
+        defined(_M_ALPHA) || defined(vax) || defined(MIPSEL) ||         \
+        defined(_ARM_) || defined(__arm__)
+#define CPU_LITTLE_ENDIAN
+#define IS_BIG_ENDIAN 0
+#define IS_LITTLE_ENDIAN 1
+#elif (defined(__BYTE_ORDER) && defined(__BIG_ENDIAN) &&                \
+       __BYTE_ORDER == __BIG_ENDIAN) ||                                 \
+        defined(__sparc) || defined(__sparc__) || defined(sparc) ||     \
+        defined(_ARCH_PPC) || defined(_ARCH_PPC64) || defined(_POWER) || \
+        defined(__POWERPC__) || defined(POWERPC) || defined(__powerpc) || \
+        defined(__powerpc__) || defined(__powerpc64__) || defined(__ppc__) || \
+        defined(__hpux)  || defined(_MIPSEB) || defined(mc68000) ||     \
+        defined(__s390__) || defined(__s390x__) || defined(sel)
+#define CPU_BIG_ENDIAN
+#define IS_BIG_ENDIAN 1
+#define IS_LITTLE_ENDIAN 0
+#else
+# error "Can't detect CPU architecture."
+#endif
+
+#if defined(__GNUC__)  && (__GNUC__ >= 4) &&  \
+        (__GNUC__ > 4 || __GNUC_MINOR__ >= 3)
+/* for GCC >= 4.3 */
+#define bswap_32(x) __builtin_bswap32(x)
+#elif !defined(__STRICT_ANSI__)
+/* general bswap_32 definition */
+static inline uint32_t bswap_32(uint32_t x) {
+        x = ((x << 8) & 0xFF00FF00) | ((x >> 8) & 0x00FF00FF);
+        return (x >> 16) | (x << 16);
+}
+#else
+#define bswap_32(x) ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >>  8) | \
+                     (((x) & 0x0000ff00) <<  8) | (((x) & 0x000000ff) << 24))
+#endif /* bswap_32 */
+
+#if defined(__GNUC__) && (__GNUC__ >= 4) && \
+        (__GNUC__ > 4 || __GNUC_MINOR__ >= 3)
+#define bswap_64(x) __builtin_bswap64(x)
+#elif !defined (bswap64)
+#if !defined(__STRICT_ANSI__)
+static inline uint64_t bswap_64(uint64_t x) {
+        union {
+                uint64_t ll;
+                uint32_t l[2];
+        } w, r;
+        w.ll = x;
+        r.l[0] = bswap_32(w.l[1]);
+        r.l[1] = bswap_32(w.l[0]);
+        return r.ll;
+}
+#else
+#error "bswap_64 unsupported"
+#endif
+#endif
+
+#ifdef CPU_LITTLE_ENDIAN
+#define htonll(x) bswap_64(x)
+#ifndef htonl
+#define htonl(x)  bswap_32(x)
+#endif
+#define ntohll(x) bswap_64(x)
+#ifndef ntohl
+#define ntohl(x)  bswap_32(x)
+#endif
+#else /* CPU_LITTLE_ENDIAN */
+#define htonll(x) (x)
+#ifndef htonl
+#define htonl(x)  (x)
+#endif
+#define ntohll(x) (x)
+#ifndef ntohl
+#define nothl(x)  (x)
+#endif
+#endif /* CPU_LITTLE_ENDIAN */
+
+#endif /* OUROBOROS_ENDIAN_H */