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+/*
+ * iterator/iter_resptype.h - response type information and classification.
+ *
+ * Copyright (c) 2007, NLnet Labs. All rights reserved.
+ *
+ * This software is open source.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of the NLNET LABS nor the names of its contributors may
+ * be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * \file
+ *
+ * This file defines the response type. DNS Responses can be classified as
+ * one of the response types.
+ */
+
+#ifndef ITERATOR_ITER_RESPTYPE_H
+#define ITERATOR_ITER_RESPTYPE_H
+struct dns_msg;
+struct query_info;
+struct delegpt;
+
+/**
+ * The response type is used to interpret the response.
+ */
+enum response_type {
+ /**
+ * 'untyped' means that the type of this response hasn't been
+ * assigned.
+ */
+ RESPONSE_TYPE_UNTYPED = 0,
+
+ /**
+ * 'answer' means that the response terminates the resolution
+ * process.
+ */
+ RESPONSE_TYPE_ANSWER,
+
+ /** 'delegation' means that the response is a delegation. */
+ RESPONSE_TYPE_REFERRAL,
+
+ /**
+ * 'cname' means that the response is a cname without the final
+ * answer, and thus must be restarted.
+ */
+ RESPONSE_TYPE_CNAME,
+
+ /**
+ * 'throwaway' means that this particular response should be
+ * discarded and the next nameserver should be contacted
+ */
+ RESPONSE_TYPE_THROWAWAY,
+
+ /**
+ * 'lame' means that this particular response indicates that
+ * the nameserver knew nothing about the question.
+ */
+ RESPONSE_TYPE_LAME,
+
+ /**
+ * Recursion lame means that the nameserver is some sort of
+ * open recursor, and not authoritative for the question.
+ * It may know something, but not authoritatively.
+ */
+ RESPONSE_TYPE_REC_LAME
+};
+
+/**
+ * Classifies a response message from cache based on the current request.
+ * Note that this routine assumes that THROWAWAY or LAME responses will not
+ * occur. Also, it will not detect REFERRAL type messages, since those are
+ * (currently) automatically classified based on how they came from the
+ * cache (findDelegation() instead of lookup()).
+ *
+ * @param msg: the message from the cache.
+ * @param request: the request that generated the response.
+ * @return the response type (CNAME or ANSWER).
+ */
+enum response_type response_type_from_cache(struct dns_msg* msg,
+ struct query_info* request);
+
+/**
+ * Classifies a response message (from the wire) based on the current
+ * request.
+ *
+ * NOTE: currently this routine uses the AA bit in the response to help
+ * distinguish between some non-standard referrals and answers. It also
+ * relies somewhat on the originating zone to be accurate (for lameness
+ * detection, mostly).
+ *
+ * @param rdset: if RD bit was sent in query sent by unbound.
+ * @param msg: the message from the cache.
+ * @param request: the request that generated the response.
+ * @param dp: The delegation point that was being queried
+ * when the response was returned.
+ * @return the response type (CNAME or ANSWER).
+ */
+enum response_type response_type_from_server(int rdset,
+ struct dns_msg* msg, struct query_info* request, struct delegpt* dp);
+
+#endif /* ITERATOR_ITER_RESPTYPE_H */