1 files changed, 74 insertions, 0 deletions
diff --git a/src/common/errors.c b/src/common/errors.c
new file mode 100644
index 0000000..f1e650d
--- /dev/null
+++ b/src/common/errors.c
@@ -0,0 +1,74 @@
+/*  Copyright (C) 2011 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "common/errors.h"
+
+/*!
+ * \brief Looks up the given id in the lookup table.
+ *
+ * \param table Lookup table.
+ * \param id ID to look up.
+ *
+ * \return Item in the lookup table with the given id or NULL if no such is
+ *         present.
+ */
+static const error_table_t *error_lookup_by_id(const error_table_t *table,
+                                               int id)
+{
+	while (table->name != 0) {
+		if (table->id == id) {
+			return table;
+		}
+		table++;
+	}
+
+	return 0;
+}
+
+const char *error_to_str(const error_table_t *table, int code)
+{
+	const error_table_t *msg = error_lookup_by_id(table, code);
+	if (msg != 0) {
+		return msg->name;
+	} else {
+		return "Unknown error.";
+	}
+}
+
+int _map_errno(int fallback_value, int arg0, ...)
+{
+	/* Iterate all variable-length arguments. */
+	va_list ap;
+	va_start(ap, arg0);
+
+	/* KNOTD_ERROR serves as a sentinel. */
+	for (int c = arg0; c != 0; c = va_arg(ap, int)) {
+
+		/* Error code matches with mapped. */
+		if (c == errno) {
+			/* Return negative value of the code. */
+			return -abs(c);
+		}
+	}
+	va_end(ap);
+
+	/* Fallback error code. */
+	return fallback_value;
+}