1 files changed, 96 insertions, 0 deletions
diff --git a/lib/irs/gai_strerror.c b/lib/irs/gai_strerror.c
new file mode 100644
index 0000000..a2b989f
--- /dev/null
+++ b/lib/irs/gai_strerror.c
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0.  If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file gai_strerror.c
+ * gai_strerror() returns an error message corresponding to an
+ * error code returned by getaddrinfo() and getnameinfo(). The following error
+ * codes and their meaning are defined in
+ * \link netdb.h include/irs/netdb.h.\endlink
+ * This implementation is almost an exact copy of lwres/gai_sterror.c except
+ * that it catches up the latest API standard, RFC3493.
+ *
+ * \li #EAI_ADDRFAMILY address family for hostname not supported
+ * \li #EAI_AGAIN temporary failure in name resolution
+ * \li #EAI_BADFLAGS invalid value for ai_flags
+ * \li #EAI_FAIL non-recoverable failure in name resolution
+ * \li #EAI_FAMILY ai_family not supported
+ * \li #EAI_MEMORY memory allocation failure
+ * \li #EAI_NODATA no address associated with hostname (obsoleted in RFC3493)
+ * \li #EAI_NONAME hostname nor servname provided, or not known
+ * \li #EAI_SERVICE servname not supported for ai_socktype
+ * \li #EAI_SOCKTYPE ai_socktype not supported
+ * \li #EAI_SYSTEM system error returned in errno
+ * \li #EAI_BADHINTS Invalid value for hints (non-standard)
+ * \li #EAI_PROTOCOL Resolved protocol is unknown (non-standard)
+ * \li #EAI_OVERFLOW Argument buffer overflow
+ * \li #EAI_INSECUREDATA Insecure Data (experimental)
+ *
+ * The message invalid error code is returned if ecode is out of range.
+ *
+ * ai_flags, ai_family and ai_socktype are elements of the struct
+ * addrinfo used by lwres_getaddrinfo().
+ *
+ * \section gai_strerror_see See Also
+ *
+ * strerror(), getaddrinfo(), getnameinfo(), RFC3493.
+ */
+
+#include <isc/net.h>
+
+#include <irs/netdb.h>
+
+/*% Text of error messages. */
+static const char *gai_messages[] = { "no error",
+				      "address family for hostname not "
+				      "supported",
+				      "temporary failure in name resolution",
+				      "invalid value for ai_flags",
+				      "non-recoverable failure in name "
+				      "resolution",
+				      "ai_family not supported",
+				      "memory allocation failure",
+				      "no address associated with hostname",
+				      "hostname nor servname provided, or not "
+				      "known",
+				      "servname not supported for ai_socktype",
+				      "ai_socktype not supported",
+				      "system error returned in errno",
+				      "bad hints",
+				      "bad protocol",
+				      "argument buffer overflow",
+				      "insecure data provided" };
+
+/*%
+ * Returns an error message corresponding to an error code returned by
+ * getaddrinfo() and getnameinfo()
+ */
+#if defined _WIN32
+char *
+#else  /* if defined _WIN32 */
+const char *
+#endif /* if defined _WIN32 */
+gai_strerror(int ecode) {
+	union {
+		const char *const_ptr;
+		char *deconst_ptr;
+	} ptr;
+
+	if ((ecode < 0) ||
+	    (ecode >= (int)(sizeof(gai_messages) / sizeof(*gai_messages))))
+	{
+		ptr.const_ptr = "invalid error code";
+	} else {
+		ptr.const_ptr = gai_messages[ecode];
+	}
+	return (ptr.deconst_ptr);
+}