Memory layout rrsets.

git-svn-id: file:///svn/unbound/trunk@230 be551aaa-1e26-0410-a405-d3ace91eadb9

doc/Changelog

@@ -1,6 +1,7 @@
 4 April 2007: Wouter
 	- moved to version 0.3.
 	- added util/data/dname.c
+	- layout of memory for rrsets.
 
 3 April 2007: Wouter
 	- detect sign of msghdr.msg_iovlen so that the cast to that type

util/data/msgreply.h

@@ -42,7 +42,9 @@
 #ifndef UTIL_DATA_MSGREPLY_H
 #define UTIL_DATA_MSGREPLY_H
 #include "util/storage/lruhash.h"
+#include "util/data/packed_rrset.h"
 struct comm_reply;
+struct alloc_cache;
 
 /**
  * Structure to store query information that makes answers to queries
@@ -61,10 +63,25 @@ struct query_info {
 	int has_cd;
 };
 
+/**
+ * Information to reference an rrset
+ */
+struct rrset_ref {
+	/** the key with lock, and ptr to packed data. */
+	struct packed_rrset_key* key;
+	/** id needed */
+	rrset_id_t id;
+};
+
 /**
  * Structure to store DNS query and the reply packet.
  * To use it, copy over the flags from reply and modify using flags from
  * the query (RD,CD if not AA). prepend ID. 
+ *
+ * Memory layout is:
+ *	o struct
+ *	o rrset_ref array
+ *	o packed_rrset_key* array.
  */
 struct reply_info {
 	/** the reply packet, skips ID and flags, 
@@ -74,6 +91,34 @@ struct reply_info {
 	size_t replysize;
 	/** the flags for the answer, host order. */
 	uint16_t flags;
+
+	/** 
+	 * network order counts: qdcount ancount nscount arcount. 
+	 * so this is wireformat for the counts as they appear in the message.
+	 * If qdcount is not 0, then it is 1, and the data that appears
+	 * in the reply is the same as the query_info.
+	 */
+	uint16_t counts[4];
+
+	/** Total number of rrsets in reply: ancount+nscount+arcount. */
+	size_t num_rrsets;
+
+	/** 
+	 * List of pointers (only) to the rrsets in the order in which 
+	 * They appear in the reply message.  
+	 * number of elements is ancount+nscount+arcount.
+	 * this is a pointer to that array. 
+	 */
+	struct packed_rrset_key** rrsets;
+
+	/** 
+	 * Packed array of ids (see counts) and pointers to packed_rrset_key.
+	 * The number equals ancount+nscount+arcount. 
+	 * These are sorted in ascending pointer, the locking order. So
+	 * this list can be locked (and id, ttl checked), to see if 
+	 * all the data is available and recent enough.
+	 */
+	struct rrset_ref ref[1];
 };
 
 /**
@@ -98,6 +143,28 @@ struct msgreply_entry {
  */
 int query_info_parse(struct query_info* m, ldns_buffer* query);
 
+/**
+ * Parse query reply.
+ * Fills in preallocated query_info structure (with ptr into buffer).
+ * Allocates reply_info and packed_rrsets. These are not yet added to any
+ * caches or anything, this is only parsing. Returns formerror on qdcount > 1.
+ * @param pkt: the packet buffer. Must be positioned after the query section.
+ * @param alloc: creates packed rrset key structures.
+ * @param rep: allocated reply_info is returned (only on no error).
+ * @param qinf: query_info is returned (only on no error).
+ * @return: zero is OK, or error code in case of error.
+ */
+int reply_info_parse(ldns_buffer* pkt, struct alloc_cache* alloc,
+	struct query_info* qinf, struct reply_info* rep);
+
+/** 
+ * Delete reply_info and packed_rrsets (while they are not yet added to the
+ * hashtables.). Returns rrsets to the alloc cache.
+ * @param rep: reply_info to delete.
+ * @param alloc: where to return rrset structures to.
+ */
+void reply_info_parsedelete(struct reply_info* rep, struct alloc_cache* alloc);
+
 /**
  * Allocate and copy the qname (obtained from query_info_parse()).
  * @param m: the queryinfo structure.

util/data/packed_rrset.c

@@ -0,0 +1,46 @@
+/*
+ * util/data/packed_rrset.c - data storage for a set of resource records.
+ *
+ * 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 contains the data storage for RRsets.
+ */
+
+#include "config.h"
+#include "util/data/packed_rrset.h"
+#include "util/log.h"
+
+

util/data/packed_rrset.h

@@ -0,0 +1,137 @@
+/*
+ * util/data/packed_rrset.h - data storage for a set of resource records.
+ *
+ * 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 contains the data storage for RRsets.
+ */
+
+#ifndef UTIL_DATA_PACKED_RRSET_H
+#define UTIL_DATA_PACKED_RRSET_H
+#include "util/storage/lruhash.h"
+
+/** type used to uniquely identify rrsets. Cannot be reused without
+ * clearing the cache. */
+typedef uint64_t rrset_id_t;
+
+/**
+ * This structure contains an RRset. A set of resource records that
+ * share the same domain name, type and class.
+ *
+ * Due to memory management and threading, the key structure cannot be
+ * deleted, although the data can be. The id can be set to 0 to store and the
+ * structure can be recycled with a new id.
+ */
+struct packed_rrset_key {
+	/** 
+	 * entry into hashtable. Note the lock is never destroyed,
+	 *  even when this key is retired to the cache. 
+	 * the data pointer (if not null) points to a struct packed_rrset.
+	 */
+	struct lruhash_entry entry;
+	/** 
+	 * the ID of this rrset. unique, based on threadid + sequenceno. 
+	 * ids are not reused, except after flushing the cache.
+	 * zero is an unused entry, and never a valid id.
+	 * Check this value after getting entry.lock.
+	 * The other values in this struct may only be altered after changing
+	 * the id (which needs a writelock on entry.lock).
+	 */
+	rrset_id_t id;
+
+	/**
+	 * The domain name. If not null (for id=0) it is allocated, and
+	 * contains the wireformat domain name.
+	 * This dname is canonicalized.
+	 * After the dname uint16_t type and uint16_t class is stored 
+	 * in wireformat.
+	 */
+	uint8_t* dname;
+	/** 
+	 * Length of the domain name, including last 0 root octet. 
+	 * The value+sizeof(uint16_t)*2 is actually allocated. 
+	 */
+	size_t dname_len;
+};
+
+/**
+ * RRset data.
+ *
+ * The data is packed, stored contiguously in memory.
+ * memory layout:
+ *	o base struct
+ *	o rr_data uint8_t* array
+ *	o rr_len size_t array
+ *	o rr_ttl uint32_t array
+ *	o rr_data rdata wireformats
+ *	o rrsig_data rdata wireformat
+ *
+ * Rdata is stored in wireformat. The dname is stored in wireformat.
+ * TTLs are stored as absolute values (and could be expired).
+ *
+ * You need the packed_rrset_key to know dname, type, class of the
+ * resource records in this RRset. (if signed the rrsig gives the type too).
+ *
+ * On the wire an RR is:
+ *	name, type, class, ttl, rdlength, rdata.
+ * So we need to send the following per RR:
+ *	key.dname, ttl, rr_data[i].
+ *	since key.dname ends with type and class.
+ *	and rr_data starts with the rdlength.
+ *	the ttl value to send changes due to time.
+ */
+struct packed_rrset {
+	/** TTL (in seconds like time()) of the rrset */
+	uint32_t ttl;
+	/** number of rrs. */
+	size_t num;
+	/** 
+	 * Array of pointers to every rr's rdata. 
+	 * The rr_data[i] rdata is stored in uncompressed wireformat. 
+	 * The first uint16_t of rr_data[i] is network format rdlength.
+	 */
+	uint8_t** rr_data;
+	/** length of every rr's rdata, rr_len[i] is size of rr_data[i]. */
+	size_t* rr_len;
+	/** TTL of every rr (equal or bigger than the rrset ttl). */
+	uint32_t* rr_ttl;
+	/** if this rrset is signed with an RRSIG, it is stored here. */
+	uint8_t* rrsig_data;
+	/** length of rrsig rdata (only examine if rrsig_data is not null) */
+	size_t rrsig_len;
+};
+
+#endif /* UTIL_DATA_PACKED_RRSET_H */