Implement our own functions to convert between host and network values

We add htonl, ntohl and ntohs which were the last symbols we relied on
from libc.

The Makefile.am file was updated to reflect the fact that we only require libgcc.
Message-Id: <Y5zNdOJ/YnyYCOhX@mars>

2 files changed, 76 insertions, 0 deletions

diff --git a/util/byteorder.c b/util/byteorder.c
new file mode 100644
index 00000000..18311972
--- /dev/null
+++ b/util/byteorder.c
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2022 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Mach.
+ *
+ * GNU Mach 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 2, 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "util/byteorder.h"
+
+uint16_t ntohs(uint16_t netshort) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	return __builtin_bswap16(netshort);
+#else
+	return netshort;
+#endif
+}
+
+uint32_t ntohl(uint32_t netlong) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	return __builtin_bswap32(netlong);
+#else
+	return netlong;
+#endif
+}
+
+uint32_t htonl(uint32_t hostlong) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	return __builtin_bswap32(hostlong);
+#else
+	return hostlong;
+#endif
+}
diff --git a/util/byteorder.h b/util/byteorder.h
new file mode 100644
index 00000000..2b780ffe
--- /dev/null
+++ b/util/byteorder.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2022 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Mach.
+ *
+ * GNU Mach 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 2, 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#ifndef _UTIL_BYTEORDER_H_
+#define _UTIL_BYTEORDER_H_
+
+#include <stdint.h>
+
+uint16_t ntohs(uint16_t netshort);
+uint32_t ntohl(uint32_t netlong);
+
+uint32_t htonl(uint32_t hostlong);
+
+#endif	/* _UTIL_BYTEORDER_H_ */