From 38638ae8dedd8f2a0f92059b30b107a44cb83298 Mon Sep 17 00:00:00 2001
From: Pierre Pronchery <khorben@defora.org>
Date: Mon, 5 Dec 2011 10:51:37 +0000
Subject: [PATCH] Initial import

---
 src/common.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 src/common.c

diff --git a/src/common.c b/src/common.c
new file mode 100644
index 0000000..b4fed56
--- /dev/null
+++ b/src/common.c
@@ -0,0 +1,104 @@
+/* $Id$ */
+/* Copyright (c) 2011 Pierre Pronchery <khorben@defora.org> */
+/* This file is part of DeforaOS System VPN */
+/* 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, version 3 of the License.
+ *
+ * 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, see <http://www.gnu.org/licenses/>. */
+
+
+
+#include "VPN.h"
+
+
+/* types */
+typedef struct _VPNErrno
+{
+	int native;
+	int error;
+} VPNError;
+
+typedef struct _VPNFlag
+{
+	unsigned int native;
+	unsigned int flag;
+} VPNFlag;
+
+
+/* variables */
+/* errors */
+static VPNError _vpn_error[] =
+{
+	{ EPERM,	VPN_EPERM	},
+	{ EBADF,	VPN_EBADF	},
+	{ EPROTO,	VPN_EPROTO	}
+};
+static const size_t _vpn_error_cnt = sizeof(_vpn_error) / sizeof(*_vpn_error);
+
+
+/* prototypes */
+static int _vpn_errno(VPNError * error, size_t error_cnt, int value,
+		int reverse);
+static int _vpn_flags(VPNFlag * flags, size_t flags_cnt, int value,
+		int reverse);
+
+
+/* functions */
+/* vpn_errno */
+static int _vpn_errno(VPNError * error, size_t error_cnt, int value,
+		int reverse)
+{
+	size_t i;
+
+	for(i = 0; i < error_cnt; i++)
+		if(reverse == 0 && value == error[i].native)
+			return -error[i].error;
+		else if(reverse != 0 && value == error[i].error)
+		{
+			errno = error[i].native;
+			return -1;
+		}
+	/* FIXME really is an unknown error */
+	if(reverse == 0)
+		return -VPN_EPROTO;
+	errno = EPROTO;
+	return -1;
+}
+
+
+/* vpn_flags */
+static int _vpn_flags(VPNFlag * flags, size_t flags_cnt, int value, int reverse)
+{
+	int ret = 0;
+	size_t i;
+
+	for(i = 0; i < flags_cnt; i++)
+		if(reverse == 0)
+		{
+			if((value & flags[i].native) == flags[i].native)
+			{
+				value -= flags[i].native;
+				ret |= flags[i].flag;
+			}
+		}
+		else if((value & flags[i].flag) == flags[i].flag)
+		{
+			value -= flags[i].flag;
+			ret |= flags[i].native;
+		}
+#ifdef DEBUG
+	fprintf(stderr, "DEBUG: %s(%p, %lu, %d, %d) => %d\n", __func__,
+			(void *)flags, flags_cnt, value, reverse, (value == 0)
+			? ret : -1);
+#endif
+	if(value != 0)
+		return -1;
+	return ret;
+}