1 files changed, 131 insertions, 0 deletions
diff --git a/byteorder.h b/byteorder.h
new file mode 100644
index 0000000..059cc70
--- /dev/null
+++ b/byteorder.h
@@ -0,0 +1,131 @@
+/*
+ * Simple byteorder handling.
+ *
+ * Copyright (C) 1992-1995 Andrew Tridgell
+ * Copyright (C) 2007-2022 Wayne Davison
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, visit the http://fsf.org website.
+ */
+
+#undef CAREFUL_ALIGNMENT
+
+/* We know that the x86 can handle misalignment and has the same
+ * byte order (LSB-first) as the 32-bit numbers we transmit. */
+#if defined __i386__ || defined __i486__ || defined __i586__ || defined __i686__ || __amd64
+#define CAREFUL_ALIGNMENT 0
+#endif
+
+#ifndef CAREFUL_ALIGNMENT
+#define CAREFUL_ALIGNMENT 1
+#endif
+
+#define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
+#define UVAL(buf,pos) ((uint32)CVAL(buf,pos))
+
+#if CAREFUL_ALIGNMENT
+
+static inline uint32
+IVALu(const uchar *buf, int pos)
+{
+	return UVAL(buf, pos)
+	     | UVAL(buf, pos + 1) << 8
+	     | UVAL(buf, pos + 2) << 16
+	     | UVAL(buf, pos + 3) << 24;
+}
+
+static inline void
+SIVALu(uchar *buf, int pos, uint32 val)
+{
+	CVAL(buf, pos)     = val;
+	CVAL(buf, pos + 1) = val >> 8;
+	CVAL(buf, pos + 2) = val >> 16;
+	CVAL(buf, pos + 3) = val >> 24;
+}
+
+static inline int64
+IVAL64(const char *buf, int pos)
+{
+	return IVALu((uchar*)buf, pos) | (int64)IVALu((uchar*)buf, pos + 4) << 32;
+}
+
+static inline void
+SIVAL64(char *buf, int pos, int64 val)
+{
+	SIVALu((uchar*)buf, pos, val);
+	SIVALu((uchar*)buf, pos + 4, val >> 32);
+}
+
+#else /* !CAREFUL_ALIGNMENT */
+
+/* This handles things for architectures like the 386 that can handle alignment errors.
+ * WARNING: This section is dependent on the length of an int32 (and thus a uint32)
+ * being correct (4 bytes)!  Set CAREFUL_ALIGNMENT if it is not. */
+
+static inline uint32
+IVALu(const uchar *buf, int pos)
+{
+	union {
+		const uchar *b;
+		const uint32 *num;
+	} u;
+	u.b = buf + pos;
+	return *u.num;
+}
+
+static inline void
+SIVALu(uchar *buf, int pos, uint32 val)
+{
+	union {
+		uchar *b;
+		uint32 *num;
+	} u;
+	u.b = buf + pos;
+	*u.num = val;
+}
+
+static inline int64
+IVAL64(const char *buf, int pos)
+{
+	union {
+		const char *b;
+		const int64 *num;
+	} u;
+	u.b = buf + pos;
+	return *u.num;
+}
+
+static inline void
+SIVAL64(char *buf, int pos, int64 val)
+{
+	union {
+		char *b;
+		int64 *num;
+	} u;
+	u.b = buf + pos;
+	*u.num = val;
+}
+
+#endif /* !CAREFUL_ALIGNMENT */
+
+static inline uint32
+IVAL(const char *buf, int pos)
+{
+	return IVALu((uchar*)buf, pos);
+}
+
+static inline void
+SIVAL(char *buf, int pos, uint32 val)
+{
+	SIVALu((uchar*)buf, pos, val);
+}